TW202240006A - Conformal and smooth titanium nitride layers and methods of forming the same - Google Patents

Abstract

The disclosed technology generally relates to forming a thin film comprising titanium nitride (TiN), and more particularly to forming by a cyclical vapor deposition process the thin film comprising (TiN). In one aspect, a method a method of forming a thin film comprising titanium nitride (TiN) by a cyclical vapor deposition process comprises forming on a semiconductor substrate a TiN thin film by exposing the semiconductor substrate to one or more cyclical vapor deposition cycles each comprising an exposure to a Ti precursor at a Ti precursor flow rate and an exposure to a N precursor at a N precursor flow rate, wherein a ratio of the N precursor flow rate to the Ti precursor flow rate exceeds 3. The method is such that the TiN thin film has a preferential (111) crystalline texture such that an X-ray spectrum of the TiN thin film has a ratio of a peak height or an intensity of an X-ray diffraction peak corresponding to a (111) crystal orientation of TiN to a peak height or an intensity of an X-ray diffraction peak corresponding to a (200) crystal orientation of TiN that exceeds 0.4. Aspects are also directed to semiconductor structures incorporating the thin film and method of forming the same.

Description

Conformal and smooth titanium nitride layer and method of forming same

The present invention relates generally to forming titanium nitride layers, and more particularly to conformal and smooth titanium nitride layers.

Titanium nitride (TiN) has been widely used in the fabrication of various structures in integrated circuits (ICs). For example, TiN has been used in diffusion barriers, various electrodes and metallization structures. This widespread use of TiN in IC fabrication can be attributed to its structural, thermal and electrical properties. As the dimensions of various IC structures shrink, TiN is formed on features with increasingly smaller dimensions and complex topologies. For example, as technology nodes scale to the 10 nm node and beyond, there is a need for TiN layers that can conformally line high aspect ratio trenches and vias with dimensions as small as a few nanometers (e.g., as diffusion barrier). Although techniques such as physical vapor deposition (PVD) and chemical vapor deposition (CVD) have been used in the IC industry for decades to form TiN, the conformal The increased demand for sex can ultimately limit their use. On the other hand, while atomic layer deposition (ALD) has been demonstrated for conformal deposition of TiN films, some electrical properties (e.g., conductivity) and physical properties (e.g., surface roughness) of the films are comparable to those obtained using methods such as TiN films formed by other methods of physical vapor deposition (PVD) may be inferior. Accordingly, there is a need for methods for forming TiN-based films for use in IC fabrication that have superior surface smoothness and step coverage relative to TiN films formed by PVD and CVD, while also having matching or superior electrical and physical properties. Atomic layer deposition method.

In one aspect, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes exposing a semiconductor substrate to respective exposures to a first Ti precursor and to a first N The exposure of the precursor to one or more first periodic vapor deposition cycles forms a first portion of the thin film on the semiconductor substrate. Additionally, the method includes exposing the semiconductor substrate to one or more second periodic vapor deposition cycles each comprising exposure to a second Ti precursor and exposure to a second N precursor to the A second portion of the film is formed on the first portion. The exposure to the Ti precursor and the N precursor during the one or more second ALD cycles relative to the corresponding exposure to one or both of the Ti precursor and the N precursor during the one or more first ALD cycles The exposure of one or both bodies is under higher pressure.

In another aspect, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes providing a semiconductor substrate comprising trenches or vias having an aspect ratio greater than one. Additionally, the method includes exposing the semiconductor substrate to one or more first periodic vapor deposition cycles each including exposure to a first Ti precursor and exposure to a first N precursor A first portion of the film is formed in the via and the film is formed in the trench or the via. In addition, the method includes exposing the semiconductor substrate to one or more second periodic vapor deposition cycles each comprising exposure to a second Ti precursor and exposure to a second N precursor to deposit the first portion of the thin film A second portion of the film is formed thereon. Relative to the corresponding exposure to one or both of the second Ti precursor and the second N precursor during the one or more second periodic vapor deposition cycles, during the one or more first periodic Exposure to one or both of the first Ti precursor and the first N precursor during a vapor deposition cycle is at different pressures.

In another aspect, a semiconductor structure includes a semiconductor substrate including non-metallic sidewall surfaces in trenches or vias having an aspect ratio exceeding 5. In addition, the semiconductor structure includes a thin film comprising TiN conformally coating the non-metallic sidewall surface, wherein formed below 25% of the height of the trench or the via and above 25% of the height of the trench or the via The ratio of the thickness of the film above exceeds 0.9.

In another aspect, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes exposing a semiconductor substrate to a Ti precursor at a Ti precursor flow rate and forming a TiN thin film on the semiconductor substrate at one or more periodic vapor deposition cycles of N precursor flow rate to N precursor exposure, wherein the ratio of the N precursor flow rate to the Ti precursor flow rate More than 3. The method makes the TiN thin film have a preferential (111) crystal texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) corresponding to TiN. The ratio of the peak height or intensity of the X-ray diffraction peaks of the crystal orientation to more than 0.4.

In another aspect, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes exposing a semiconductor substrate to a Ti precursor at a Ti precursor flow rate and one or more periodic vapor deposition cycles of exposure to N precursor at a N precursor flow rate to form a TiN film on the semiconductor substrate, wherein the N precursor flow rate exceeds 500 sccm. The method makes the TiN thin film have a preferential (111) crystal texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) corresponding to TiN. The ratio of the peak height or intensity of the X-ray diffraction peaks of the crystal orientation to more than 0.4.

In another aspect, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes exposing a semiconductor substrate to a Ti precursor at a Ti precursor flow rate and one or more periodic vapor deposition cycles of exposure to the N precursor at the N precursor flow rate to form a TiN thin film on the semiconductor substrate. Additionally, the method includes exposing the semiconductor substrate to one of exposure to a second Ti precursor at a second Ti precursor flow rate and exposure to a second N precursor at a second N precursor flow rate by exposing the semiconductor substrate to or a plurality of second periodic vapor deposition cycles to form a second TiN thin film on the TiN thin film. The method makes one or both of the TiN thin film and the second TiN thin film have a preferential (111) crystal texture, so that the X-ray spectrum of one or both of the TiN thin film and the second TiN thin film has a corresponding TiN ( 111) The ratio of the peak height or intensity of the X-ray diffraction peak of the crystal orientation to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN exceeds 0.4.

In another aspect, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes exposing a semiconductor substrate to a temperature each comprising a first Ti precursor flow rate to a first TiN Precursor exposure and one or more first periodic vapor deposition cycles of exposure to the first N precursor at a first N precursor flow rate to form a first TiN thin film on the semiconductor substrate at a first pressure . The first TiN thin film has a crystalline texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the X-ray corresponding to the (200) crystal orientation of TiN The ratio of the peak height or intensity of diffraction peaks exceeding 0.4. Additionally, the method includes exposing the semiconductor substrate to one of exposure to a second Ti precursor at a second Ti precursor flow rate and exposure to a second N precursor at a second N precursor flow rate by exposing the semiconductor substrate to or a plurality of second periodic vapor deposition cycles to form a second TiN film on the first TiN film at a second pressure higher than the first pressure.

In another aspect, a semiconductor structure includes a semiconductor substrate including non-metallic sidewall surfaces in trenches or vias having an aspect ratio exceeding 5. Additionally, the semiconductor structure includes a thin film comprising TiN conformally coating the non-metallic sidewall surface, wherein the thin film has a preferential (111) crystallographic texture such that the X-ray diffraction profile of the thin film has an orientation corresponding to a (111) crystallographic orientation The ratio of the peak height or intensity of the X-ray diffraction peak to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation exceeds 0.4.

Incorporation by reference of any priority application

Any and all applications for which foreign or domestic priority claims are identified in the Application Data Sheet as filed with this application are hereby incorporated by reference pursuant to 37 CFR 1.57.

This application is a continuation-in-part of U.S. Application Serial No. 16/595,945, filed October 8, 2019, entitled "CONFORMAL AND SMOOTH TITANIUM NITRIDE LAYERS AND METHODS OF FORMING THE SAME," pursuant to 35 U.S.C. § 119 (e) To claim priority to U.S. Provisional Patent Application No. 63/123,733, filed on December 10, 2020, entitled "CONFORMAL AND SMOOTH TITANIUM NITRIDE LAYERS AND METHODS OF FORMING THE SAME," the entire contents of which are The manner of reference is expressly incorporated herein.

As described above, there is a need in the integrated circuit (IC) industry for smooth and conformal TiN films with superior electrical and physical properties, and methods of forming such films. To address these and other needs, disclosed herein are smooth and conformal thin films comprising TiN, and periodic vapor deposition methods for forming such films that exhibit conformality of films deposited by periodic vapor deposition procedures characteristics, while also having electrical and physical properties superior to or matching those of TiN films formed by existing physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods. In particular, the method of forming a thin film comprising titanium nitride (TiN) includes exposing a semiconductor substrate to one or more first periods each comprising exposure to a first Ti precursor and exposure to a first N precursor A permanent vapor deposition cycle is used to form a first portion of the thin film on the semiconductor substrate. In addition, the method includes exposing the semiconductor substrate to one or more second periodic vapor deposition cycles each comprising exposure to a second Ti precursor and exposure to a second N precursor on the first A second portion of the film is formed on one portion. During the one or more second periodic cycles, compared to the corresponding exposure to one or both of the first Ti precursor and the first N precursor during the one or more first periodic vapor deposition cycles, during the one or more second periodic cycles Exposure to one or both of the second Ti precursor and the second N precursor is varied during the active vapor deposition cycle. The periodic vapor deposition process disclosed herein is sometimes referred to as atomic layer deposition (ALD). However, periodic vapor deposition procedures are not limited to atomic layer deposition procedures. For example, in various embodiments described herein, the precursor can partially or substantially saturate the reaction surface.

By exposing the substrate to Ti and/or N precursors at relatively low pressures (e.g., less than 3 Torr) during deposition of the first portion of the thin film, initial film growth can proceed substantially in a layer-by-layer growth mode, whereby Advantageously results in lower average grain size and surface roughness relative to comparable TiN films deposited by exposing the substrate to Ti and/or N precursors at higher pressures (e.g., greater than 3 Torr or 5 Torr) Spend. On the other hand, by exposing the substrate to Ti and/or N precursors at relatively high pressures (e.g., greater than 3 Torr) during deposition of the second portion of the thin film, a portion after film growth advantageously results in Comparable TiN films deposited from exposing substrates to Ti and/or N precursors at relatively low pressures (eg, less than 3 Torr or less than 1 Torr) have higher conformality or step coverage.

Additionally, since the first portion of the TiN film is grown in a layer-by-layer mode, the second portion of the film can be grown using the second A portion acts as a template to grow in a layer-by-layer pattern.

As a final result, when deposited on a specific surface (e.g., a surface including a non-metallic surface), including by using methods according to the methods disclosed herein for one or both of the Ti precursor and N precursor The thin films of the first and second portions deposited at different corresponding exposure pressures advantageously have a combination of surface roughness and conformality superior to thin film layers formed on the same surface using a single pressure. Alternatively or additionally, due in part to the improved smoothness and conformality, the thin films have relatively lower resistivity compared to TiN layers formed by some prior methods.

As described herein, unless expressly limited, a compound referred to by its constituent elements not having their specific stoichiometric ratios should be understood to encompass all possible non-zero concentrations of the respective elements. For example, titanium nitride (TiN) should be understood to cover all possible stoichiometric and non-stoichiometric compositions of titanium nitride that can be expressed by the general formula Ti _x N, where x > 0, including TiN, Ti ₃ N ₄ , Ti ₄ N ₃ , Ti ₆ N ₅ , Ti ₂ N and TiN ₂ and other non-stoichiometric compositions of Ti and N.

As described above, titanium nitride (TiN) plays an important role in integrated circuit (IC) fabrication. Although techniques such as Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD) have been used in the IC industry to deposit TiN, it is difficult to use TiN for forming TiN with high conformality without significant damage to electrical and physical properties. There has been an increasing demand for methods of deposition of films based on these materials.

Additionally, while plasma-enhanced processes such as plasma-enhanced atomic layer deposition (PE-ALD) are effective in forming conformal films on surfaces with relatively low aspect ratios, such processes may not be effective on surfaces with Relatively high aspect ratio vias and deposited films inside cavities. Without being bound by theory, one possible reason for this is that, under some circumstances, the plasma or its active species may not be able to reach the deeper portions of the high aspect ratio vias. In these circumstances, different parts of the via may be exposed to different amounts of plasma or its active species, leading to undesired structural effects of non-uniform deposition, such as sharpening compared to deeper parts (sometimes referred to as peaking). or keyhole formation), a thicker film is deposited near the opening of the via. For these reasons, thermal ALD can be more advantageous because thermal ALD does not depend on the ability of the plasma or its active species to reach the portion of the surface on which it is deposited.

However, while thermal ALD techniques may be suitable for forming relatively conformal TiN films on topography, especially topography with relatively high aspect ratios (e.g., exceeding 1:1), the inventors have realized that by TiN films formed by thermal ALD may be inferior to TiN films formed by PVD or CVD in certain aspects, such as film roughness and resistivity. In this regard, the inventors have discovered that some electrical and/or physical properties of ALD grown TiN-based films can be affected by the growth mode. In particular, the inventors have discovered that while it may be desirable to grow TiN-dominated films in ALD in a two-dimensional layer-by-layer growth mode, this layer-by-layer growth mode may not be readily achievable in some circumstances. The present inventors have further discovered that the growth of TiN-dominated films by ALD in layer-by-layer growth mode presents particular challenges in IC fabrication, where on non-metallic surfaces, especially insulating surfaces such as oxide and nitride surfaces, or semiconductor TiN-dominated films are formed on surfaces such as doped and undoped silicon surfaces. The inventors have realized that the extent to which TiN-dominated films can be grown in a layer-by-layer growth mode may in turn depend on the initial growth mode, which depends on the type of surface, as described herein with reference to FIGS. 1A-1D , without wishing to be bound by any theory.

Figure 1A schematically depicts the nucleation of a TiN layer and Figures 1B-1D depict different growth modes of the TiN layer on different surfaces. Referring to FIG. 1A, once the precursor molecules 104 reach the surface of the substrate 100, they are physically adsorbed on the surface. Some of the adsorbed molecules 104 may diffuse along the surface of the substrate 100 until they wait to reach energetically favorable sites to be chemisorbed. The surface diffusion is governed inter alia by the substrate temperature, the substrate material and the kinetic energy of the adsorbed molecules. When the size of the nucleus formed by chemisorbed molecules exceeds a certain size (sometimes referred to as the "critical size") determined by the trade-off between bulk free energy and surface energy, the nucleus can become energetically stable , and begin to grow in size. Thus, the thus formed layer 108 of stable nuclei continues to grow by incorporating additional precursor molecules 104 . Subsequent film growth can be classified according to different growth modes schematically depicted in Figures 1B-1D.

Figure IB schematically depicts the three-dimensional island growth pattern (sometimes referred to as the Volmer-Weber growth pattern) leading to the formation of a layer 112 of three-dimensional islands. Without being bound by any theory, when the net surface free energy associated with a three-dimensional island is positive, the island growth mode can dominate, indicating that deposited atoms are more deposited than bound to the substrate. firmly bonded to each other. It will be appreciated that the energetics of ALD growth of a TiN layer may favor an island growth mode, for example, when a TiN metal layer is deposited on some semiconductor and/or insulating material surfaces.

FIG. 1C illustrates a layer-by-layer growth mode (sometimes referred to as the Frank-van der Merwe growth mode) that results in the formation of a relatively smooth two-dimensional layer 116 . Without being bound by any theory, this layer-by-layer growth mode may dominate when the deposited atoms are more strongly bound to the substrate than to each other, making it energetically favorable to stabilize the two-dimensional layer 116 . The layer-by-layer growth mode can be maintained when the bonding energy between layers decreases continuously from the first monolayer to the bulk crystal value of the TiN layer.

While FIGS. 1B and 1C are two different possible growth modes for thin films, it will be appreciated that in some circumstances growth modes intermediate between layer-by-layer and three-dimensional growth modes are possible. Figure ID shows an example of an intermediate growth pattern known as the Stranski-Krastanov (SK) growth pattern. Without being bound by any theory, SK growth can occur in thin film growth starting in layer-by-layer mode. When layer-by-layer growth becomes unfavorable after the formation of one or more monolayers, the island growth mode becomes dominant over the layer-by-layer growth mode, resulting in a thin-film structure in which three-dimensional islands are formed on a two-dimensional initial layer 120 . The SK growth mode can occur as a strain relaxation mechanism (strain-induced roughening).

In addition to the interaction between the deposit and the substrate, other factors such as substrate temperature, reactor pressure, and deposition rate can significantly affect the nucleation and early growth process, which in turn affects the final nanostructure or microstructure of the resulting film . For example, deposition conditions that enhance surface diffusion (eg, relatively higher substrate temperatures, relatively lower pressures, and/or lower deposition rates) can promote growth in a layer-by-layer mode. Thus, as disclosed herein, initial film growth according to embodiments may continue substantially in a layer-by-layer growth mode by, for example, enhancing surface diffusion during deposition of the initial portion of the TiN film by reducing pressure and growth rate conduct.

It was found that when TiN is grown by ALD on various surfaces of interest in IC fabrication, such as dielectric and semiconductor surfaces, ALD growth is initiated in a three-dimensional island growth mode or SK growth mode. For example, in some circumstances, ALD growth of TiN on the surface of a substrate comprising doped and undoped Si, _SiO2 , Si3N4, and other high _- K or low _- K materials can be in island growth mode or SK Growth mode continues. The present inventors have found that, due in part to the initial growth mode of the island growth mode or the SK growth mode, subsequent growth of TiN by ALD generally results in ultrathin conformal TiN for various applications that are useful for high aspect ratio structures. The desired film morphology is as shown in FIG. 2 .

Figure 2 is a cross-sectional transmission electron micrograph of a TiN layer grown by thermal ALD on a Si substrate coated with native oxide. After an initial film grown in a three-dimensional island or SK growth mode, ALD growth of TiN is usually characterized by the competitive growth of adjacent crystals with different orientations, which in some cases results in a V close to that of the nucleation layer. shape grains and eventually form columnar morphology with higher film thickness. As depicted in Figure 2, the resulting film morphology includes faceted pillar tops causing significant surface roughness and pillar boundaries with a lower density relative to the grains. It will be appreciated that such pillar boundaries may have significantly poorer diffusion barrier properties relative to the grains themselves, and may serve as the path of least resistance for transporting unwanted contaminants through the TiN layer.

The present inventors have discovered that when an initial portion of a TiN layer is formed on a non-metallic surface by exposing the substrate to Ti and/or N precursors at relatively low pressures (e.g., less than 1 Torr), The initial three-dimensional or SK growth mode can be suppressed and the layer-by-layer growth mode can be promoted in the initial stage (eg, nucleation stage). This may be because, among other reasons, the local diffusion of the adsorbed Ti and N precursor molecules has more time to diffuse locally and wet the substrate surface (especially non-metallic surfaces) with a relatively low contact angle. TiN layers grown at relatively low exposure pressures result in layers that uniformly cover large areas of the non-metallic surface with virtually no formation of islands, making the initial growth phase more favorable to a layer-by-layer growth mode on the substrate surface , on the substrate surface, ALD TiN will generally favor the 3D island or SK growth modes as described above. Thus, by initiating ALD of TiN by exposing the substrate to Ti and/or N precursors at relatively low precursor exposure pressures (e.g., less than 3 Torr), the resulting initial layer can be grown in a layer-by-layer mode (e.g., during the nucleation stage). Subsequent bulk growth stages, which can be continued by exposing the substrate to Ti and/or N precursors at relatively high precursor exposure pressures (eg, greater than 3 Torr), can continue in a layer-by-layer mode. By using the method according to the embodiments, some disadvantages of the conventional ALD of TiN can be avoided, especially in inorganic layers of some semiconducting and/or insulating materials, including especially Si, SiO ₂ and/or Si ₃ N ₄ , by ALD. ), this can generally be associated with initial growth characterized by island or SK growth modes as described above followed by columnar growth.

3A schematically depicts a flowchart of an atomic layer deposition method 300 for forming a TiN layer by exposing a substrate to a plurality of cycles with different corresponding precursor exposure pressures, according to an embodiment. The resulting film can have at least two regions formed at different corresponding exposure pressures. 3B schematically depicts a semiconductor structure 350 comprising a TiN layer formed by an atomic layer deposition method in which the substrate is exposed to a plurality of cycles with different corresponding precursor exposure pressures according to the method depicted in FIG. 3A Cross-sectional view. Referring to FIG. 3A , method 300 includes providing 310 a substrate including a non-metallic surface in a reaction chamber configured for ALD (eg, thermal ALD). Additionally, method 300 includes an initial phase (e.g., a nucleation phase) comprising exposing the semiconductor substrate to each of the first Ti precursor and the first N precursor by exposing the semiconductor substrate at a first respective exposure pressure. One or more first ALD cycles form 320 a first portion of the film on the substrate. The method 300 further includes a later stage (e.g., a bulk deposition stage) comprising exposing the semiconductor substrate to one or more of each including exposures to a second Ti precursor and a second N precursor under second respective exposures. A second ALD cycle forms 330 a second portion of the film on the first portion of the film. The exposure to the Ti precursor and the N precursor during the one or more second ALD cycles relative to the corresponding exposure to one or both of the Ti precursor and the N precursor during the one or more first ALD cycles Exposure to one or both is at higher pressures.

Referring to FIG. 3B , a cross-sectional view of a semiconductor thin film structure 350 including a substrate 360 , which in turn includes a non-metallic surface, eg, a dielectric and/or a semiconductor surface. A first portion 370 of a thin film comprising TiN is formed on the substrate 360 and a second portion 380 of the thin film is formed on the first portion 370 . The first and second portions 370, 380 are formed by the atomic layer deposition method depicted in FIG. 3A in which the substrate 360 is exposed to first and second cycles having different corresponding precursor exposure pressures. Since the first portion 370 can be grown in a layer-by-layer growth mode in an initial stage (e.g., a nucleation stage) as discussed above, at least the first portion 370 or both the first and second portions 370, 380 can be substantially free of defects. Neighboring crystals with different orientations characterized by columnar growth of V-shaped grains and relatively high (eg, 10% of thickness) surface roughness. Relative to comparable thin film layers formed under a single pressure during the nucleation and bulk deposition stages, the resulting TiN layer has properties including relatively higher conformality or step coverage, lower surface roughness, smaller average grain size, The superior properties of one or more of higher conductivity and/or barrier properties.

As described herein and throughout the specification, it will be appreciated that semiconductor substrates on which TiN thin films according to embodiments are formed can be implemented with a variety of substrates, including but not limited to doped semiconductor substrates that can be formed from Group IV element materials (e.g., Si, Ge, C, or Sn) or alloys formed of group IV materials (e.g., SiGe, SiGeC, SiC, SiSn, SiSnC, GeSn, etc.); III-V group compound semiconductor materials (e.g., GaAs, GaN, InAs, etc.) or alloys formed by III-V materials; II-VI semiconductor materials (CdSe, CdS, ZnSe, etc.) or alloys formed by II-VI materials.

According to some embodiments, the substrate may also be implemented as a semiconductor-on-insulator, such as a silicon-on-insulator (SOI) substrate. SOI substrates typically include silicon-insulator-silicon structures in which the various structures described above are isolated from a supporting substrate using an insulator layer such as a buried _SiO2 layer. Additionally, it will be appreciated that various structures described herein may be formed at least in part in an epitaxial layer formed at or near a surface region.

In addition, the substrate may include various structures formed thereon, such as diffusion regions, isolation regions, electrodes, vias, and lines, to name a few, on which any structure including the TiN layer according to the embodiment may be formed, Topological features (such as vias, cavities, holes or trenches) having one or more semiconductor or dielectric surfaces are included. Thus, non-metallic surfaces on which a TiN layer according to embodiments is formed may include: semiconductor surfaces, such as doped or undoped Si surfaces; and/or dielectric surfaces, such as interlayer Dielectric (ILD) surfaces, mask or hard mask surfaces, or gate dielectric surfaces, which may contain inorganic insulators, oxides, nitrides, high-K dielectrics, low-K dielectrics, or carbon, only A few examples of dielectric materials.

As described herein and throughout the specification, a reactor chamber refers to any suitably configured for thermal atomic layer deposition (ALD), including a single wafer processing reaction chamber or a batch of wafer processing reaction chambers. reaction chamber. In a thermal ALD reactor, the substrate can be placed on a suitable substrate holder such as a susceptor or a carrier boat. The substrate can be heated directly by conduction through a heated susceptor, or indirectly by radiation from a radiation source, such as a lamp, or by convection through a heated chamber wall.

Typically, in an ALD process, reactants or precursors (eg, oxidized and reduced reactants) are alternately introduced into a reaction chamber in which a substrate is disposed. The introduction of one or more reactants or precursors may then be alternated with purge and/or extraction procedures for removing excess reactants or precursors from the reaction chamber. The reactants may be introduced into the reaction chamber for a suitable period of time under conditions such that the surface of the substrate becomes at least partially saturated with the precursors or reactants and/or reaction products of the reactants. Excess or residual precursors or reactants can then be removed from the substrate, such as by purging and/or withdrawing the reaction chamber. The pumping procedure can be performed by a suitable vacuum pumping procedure and the purging step can be performed by introducing a non-reactive or inert gas, such as nitrogen or a noble gas, into the reaction chamber. In the context of layers formed by thermal ALD in the examples below, there are generally two types of precursors or reactants, nitrogen (N) precursors and titanium (Ti) precursors.

In the following, referring to FIG. 4 , according to an embodiment, a layer comprising TiN having at least two regions formed by exposing the substrate to a plurality of cycles with different corresponding precursor exposure pressures is formed by ALD (eg, thermal ALD). An exemplary embodiment of a thin film method 300 (FIG. 3A). Atomic layer deposition of TiN by exposing substrates to multiple cycles with different corresponding precursor exposure pressures

Referring again to FIG. 3A , after providing 310 a substrate comprising a non-metallic surface (substrate 360 in FIG. 3B ) in a reaction chamber, the method 300 continues by exposing the semiconductor substrate by atomic layer deposition (ALD) (e.g., thermal ALD). A first portion of the film is formed 320 on the non-metallic surface to one or more first ALD cycles, followed by forming a second portion of the film by exposing the semiconductor substrate to one or more second ALD cycles. In the following, the exposure pressures applied during the first and second ALD cycles are described graphically.

FIG. 4 diagrammatically depicts a first cycle 400A or stage (e.g., a nucleation stage) corresponding to a first portion 370 (FIG. 3B) for forming a thin film and a second cycle for forming a thin film, according to various embodiments. Pressure trace 400 of substrate to Ti and N precursor exposure during a second cycle 400B or phase (eg, bulk growth phase) of portion 380 (FIG. 3B). Referring to FIG. 4 , by exposing the semiconductor substrate to one or more exposures 404 or exposure pulses each comprising a partial pressure to the first Ti precursor and one or more exposures 408 or exposures to the first N precursor One or more first ALD cycles 400A are pulsed to form the first portion of the film. By exposing the semiconductor substrate to one or more exposures 412 or pulses of exposure each comprising a partial pressure to a second Ti precursor and one or more exposures 416 or pulses of exposure to a partial pressure to a second N precursor A plurality of second ALD cycles 400B are used to form the second portion of the thin film.

As schematically depicted, each of the exposure 404 to the first Ti precursor, the exposure 408 to the first N precursor, the exposure 412 to the second Ti precursor, and the exposure 416 to the second N precursor can have different Partial pressure regimes (regime) include corresponding partial pressure rise states 404A, 408A, 412A, and 416A, main exposure states 404B, 408B, 412B, and 416B, and partial pressure drop states 404C, 408C, 412C, and 416C. Each of the partial pressure rise states 404A, 408A, 412A, and 416A may correspond to, for example, a respective precursor introduced into the reaction chamber. Each of the main exposure states 404B, 408B, 412B, and 416B may correspond to a period during which the amount of the respective precursor in the reaction chamber is relatively constant. For example, pressure sensors or throttle valves can be used to maintain relatively constant amounts of the respective precursors. Each of the partial pressure drop states 404C, 408C, 412C, and 416C may correspond to, for example, the state when the respective precursors are purged or drawn from the reaction chamber.

Still referring to FIG. 4 , it will be appreciated that, in some implementations, the precursor may be extracted and/or purged after each exposure. In some embodiments where the precursors can be drawn out without purging, the reaction chamber pressure can be represented substantially by the partial pressure of the respective precursors, and the pressure traces for exposures 404, 408, 412, and 416 can be represented substantially at Reaction chamber pressure or precursor partial pressure during the respective exposure periods. In some embodiments where the precursor is purged with an inert gas without evacuating the precursor, the reaction chamber pressure can be represented by the total reaction chamber pressures 404P, 408P, 412P, and 416P corresponding to exposures 404, 408, 412, and 416, where The total reaction chamber pressures are derived from the respective precursor and inert gas mixtures.

In fact, a combination of pumping and purging can be used for higher throughput and improved membrane quality. In these embodiments, the substrate may be subjected to a first Ti precursor, a first N precursor, a second Ti precursor, and Partial pressure of the second N precursor. In some embodiments, the total chamber pressure can be kept relatively constant throughout a given precursor exposure or exposure pulse while adjusting the pumping power using a pressure sensor and replacing the removed precursor with an inert gas. In such embodiments, each of the one or more first ALD cycles 400A used to form the first portion (370 in FIG. 3B ) may include one or more exposures 404 (at The measured parameter may be the total reaction chamber pressure 404P), and one or more exposures 408 to the partial pressure of the first N precursor (when the measured parameter may be the total reaction chamber pressure 408P). Similarly, one or more second ALD cycles 400B for forming the second portion (380 in FIG. 3B ) may each include one or more exposures 412 to the partial pressure of the second Ti precursor (after measured The parameter may be the total pressure 412P), and one or more exposures 416 to the partial pressure of the second N precursor (where the measured parameter may be the total pressure 416P).

According to various embodiments, the measured total reaction chamber pressure may be proportional to the partial pressure of the precursor during exposure to the precursor. Thus, the higher total pressures 412P and 416P relative to the total pressures 404P and 408P, respectively, correspond to higher partial pressures of the second Ti precursor and the second N precursor relative to the first Ti precursor and the first N precursor, respectively. points of pressure. However, embodiments are not limited thereto and in other embodiments, higher total pressures 412P and 416P relative to total pressures 404P and 408P, respectively, may correspond to a second Ti precursor and a second N precursor relative to the first Partial pressures of the Ti precursor and the first N precursor are the same or lower.

Referring again to the illustrated method 300 in FIG. 3A , the correspondence with respect to the exposure pressure of the first Ti precursor and the first N precursor during the initial (e.g., nucleation phase) one or more first ALD cycles One or both, one or both of the exposure pressures of the second Ti precursor and the second N precursor during one or more of the second ALD cycles at a later stage (e.g., bulk deposition stage) are higher . In some embodiments, the exposure pressure can be the partial pressure of the precursor or the total pressure of the reaction chamber. Thus, in various embodiments, referring to FIG. 4 , the exposure 412 to the second Ti precursor is relative to a corresponding one or both of the exposure 404 to the first Ti precursor and the exposure 408 to the first N precursor, respectively. Either or both of the exposure 416 to the second N precursor may be at a higher partial pressure and/or a higher total reaction chamber pressure.

Still referring to FIG. 4 , in various embodiments, the corresponding partial or total pressures between the corresponding exposures to the Ti and N precursors during the first and second cycles 400A and 400B may be in the partial pressure rise state 404A, 408A, 412A, and 416A, the corresponding partial or total pressure during any of the main exposure states 404B, 408B, 412B, and 416B, and the partial pressure drop states 404C, 408C, 412C, and 416C. For example, relative to the exposures 404, 408 to one or both of the first Ti precursor and the first N precursor during the main exposure states 404B and 408B, respectively, during the first ALD cycle 400A, in the second ALD cycle 400B The exposures 412, 416 during the main exposure states 412B and 416B, respectively, to one or both of the second Ti precursor and the second N precursor may be at higher total or partial pressures. In various other embodiments, the corresponding partial or total pressures between the corresponding exposures to the Ti and N precursors during the first and second cycles 400A and 400B may be Corresponds to mean, mean or peak partial pressure or total pressure.

Still referring to FIG. 4 , in the illustrated embodiment, the total pressure and/or partial pressure during exposure 404 to the first Ti precursor and exposure 408 to the first N precursor are different, and during exposure to the second The total and/or partial pressures during the exposure 412 of the Ti precursor to the exposure 416 of the second N precursor are different. However, embodiments are not so limited and in some embodiments, the total pressure and/or partial pressure during the exposure 404 to the first Ti precursor and the exposure 408 to the first N precursor can be kept constant, and/or The total pressure and/or partial pressure during the exposure 412 to the second Ti precursor and the exposure 416 to the second N precursor can be kept constant.

Still referring to FIG. 4 , each of the total pressure during the exposure 404 to the first Ti precursor and the exposure 408 to the first N precursor, which may be the same or different, may be 0.01 Torr to 0.2 Torr, 0.2 Torr to 0.4 Torr, 0.4 Torr to 0.6 Torr, 0.6 Torr to 0.8 Torr, 0.8 Torr to 1.0 Torr, 1.0 Torr to 1.5 Torr, 1.5 Torr to 2.0 Torr, 2.0 Torr to 2.5 Torr, 2.5 Torr to 3.0 Torr or by The pressure within the range defined by any one of the equivalent values. Each of the total pressure during exposure 412 to the second Ti precursor and exposure 416 to the second N precursor, which may be the same or different, may be 3.0 to 4.0 Torr, 4.0 to 5.0 Torr, 5.0 Torr to 6.0 Torr, 6.0 Torr to 7.0 Torr, 7.0 Torr to 8.0 Torr, 8.0 Torr to 9.0 Torr, 9.0 Torr to 10.0 Torr, 10.0 Torr to 11.0 Torr, 11.0 Torr to 12.0 Torr or any of these values The pressure within the defined range. The ratio of the total pressure of the reaction chamber (measured in Torr) during the exposure 412 to the second Ti precursor and the exposure 404 to the first Ti precursor can be 2 to 5, 5 to 10, 10 to 20 , 20 to 50, 50 to 100, or within a range defined by any of these values. Similarly, the ratio of the total pressure of the reaction chamber during the exposure 416 to the second N precursor and the exposure 408 to the first N precursor may be 2 to 5, 5 to 10, 10 to 20, 20 to 50, 50 to 100, or within the range defined by any of these values. In each of exposures 404, 408, 412, and 416, the respective Ti or N precursor may constitute 1% to 2%, 2% to 5%, 5% to 10% of the total amount of gas molecules in the reaction chamber , 10% to 20%, 20% to 50%, 50% to 100%, or a percentage within a range defined by any of these values.

Still referring to FIG. 4 , according to various embodiments, the total pressure or partial pressure during the exposure 404 to the first Ti precursor and the exposure 408 to the first N precursor, as well as the flow rates of the respective precursors and inert gases, and The pumping power of the reaction chamber is such that the deposition rate during the first cycle 400A or phase ranges from 0.10 Å/cycle to 0.20 Å/cycle per cycle comprising exposure 404 to the first Ti precursor and exposure 408 to the first N precursor. Å/cycle, 0.20 Å/cycle to 0.30 Å/cycle, 0.30 Å/cycle to 0.40 Å/cycle, 0.40 Å/cycle to 0.50 Å/cycle, 0.50 Å/cycle to 0.60 Å/cycle or by A value within the range defined by either of them. The total pressure or partial pressure during the exposure 412 to the second Ti precursor and the exposure 416 to the second N precursor, as well as the flow rates of the respective precursors and inert gases and the pumping power of the reaction chamber are controlled such that at The deposition rate during the second cycle 400B or stage is 0.20 Å/cycle to 0.30 Å/cycle, 0.30 Å/cycle to 0.40 Å per cycle comprising exposure 404 to the first Ti precursor and exposure 408 to the first N precursor /cycle, 0.40 Å/cycle to 0.50 Å/cycle, 0.50 Å/cycle to 0.60 Å/cycle, 0.60 Å/cycle to 0.70 Å/cycle, 0.70 Å/cycle to 0.80 Å/cycle, or between A value within the range defined by either. The ratio of the deposition rate per cycle during the second cycle 400B to the deposition rate per cycle during the first cycle 400A may be 1 to 1.5, 1.5 to 2.0, 2.5 to 3.0, or anywhere between such values. ratio within the range defined by the

The inventors have discovered that when each of forming 320 ( FIG. 3A ) a first portion 370 ( FIG. 3B ) of a thin film comprising TiN and forming 330 ( FIG. 3A ) a second portion 380 ( FIG. 3B ) of the thin film comprises making the semiconductor substrate 1 to 25 cycles, 26 to 50 cycles, 50 to 100 cycles, 100 to 200 cycles, 200 From 1 to 300 cycles, from 300 to 400 cycles, from 400 to 500 cycles, from 500 to 600 cycles, or at a value within the range defined by any of these values, the values described herein can be achieved Various technical advantages of the disclosed TiN thin films. According to various embodiments, the ratio of the number of second cycles to the number of first cycles may be greater than 1, 2, 5 or 10 or a ratio within a range defined by any of these values, or less than 1, 0.5, 0.1 or a ratio within a range defined by any of these values. The total thickness of the film comprising the first portion 370 ( FIG. 3B ) and the second portion 380 ( FIG. 3B ) including TiN may have a thickness of no more than about 25 nm, 20 nm, 15 nm, 10 nm, 7 nm, 4 nm, 2 nm or a combined stack thickness having a value within the range defined by any of these values. The thickness ratio between the first portion 370 (FIG. 3B) and the second portion 380 (FIG. 3B) may be about 1:20 to 1:10, 1:10 to 1:5, 1:5 to 1:2, 1:20 2 to 1:1, 1:1 to 2:1, 2:1 to 5:1, 5:1 to 10:1, 10:1 to 20:1 or defined by any of these values ratio within the range. It will be appreciated that in some embodiments, for example, when higher conformality may be more important than lower film roughness, first portion 370 ( FIG. 3B ) may be relatively thin, while in other embodiments, for example, When lower film roughness may be more important than higher conformality, second portion 380 (FIG. 3B) may be relatively thin.

Still referring to FIG. 4 , each of the exposure 404 of the substrate to the first Ti precursor and the exposure 412 of the substrate to the second Ti precursor is such that the surface of the substrate is substantially rendered substantially flat with the first Ti precursor or the second Ti precursor, respectively. or partially saturated. After each of the exposure 404 of the substrate to the first Ti precursor and the exposure 412 of the substrate to the second Ti precursor, excess or residual first Ti And/or the reaction product of the second Ti precursor or the like.

Similarly, each of the exposure 408 of the substrate to the first N precursor and the exposure 416 of the substrate to the second N precursor is such that the substrate is substantially or partially saturated with the first N precursor or the second N precursor, respectively. After each of the exposure 408 of the substrate to the first N precursor and the exposure 416 of the substrate to the second N precursor, excess or residual first And/or the reaction product of the second N precursor or the like. Subjecting the substrate to one or more exposures to the first Ti precursor and one or more exposures to the first N precursor can form about one monolayer or less per TiN cycle. Similarly, subjecting the substrate to one or more exposures to a second Ti precursor and one or more exposures to a second N precursor can form about one monolayer or less per TiN cycle.

In some embodiments, the exposure 404 to the first Ti precursor, the exposure 408 to the first N precursor, the exposure 412 to the second Ti precursor, and/or the exposure 416 to the second N precursor may be at other The introduction of the precursor is performed sequentially multiple times. For example, it may be advantageous that exposing the substrate more than once to a Ti precursor and/or N precursor may result in higher surface saturation levels in some circumstances, eg, when substantial steric effects are present.

Still referring to FIG. 4 , it will be appreciated that the relative order of exposure to the first Ti precursor and to the first N precursor may be selected depending on competing conditions. In some embodiments, the first Ti precursor may advantageously be the first precursor to which the substrate surface is exposed. For example, one or more direct exposures of the Si surface to the first Ti precursor can result in the formation of one or more monolayers of TiSi and prevent the formation of SiN, which in turn can be beneficial in reducing the relationship between the underlying Si and the TiN layer formed above it. contact resistance between them. However, in some other embodiments, the first N precursor may advantageously be the first precursor to which the substrate is exposed. For example, by directly exposing the Si substrate to the first N precursor, one or more monolayers of SiN can be intentionally formed, which can be beneficial to improve the barrier properties of the stack.

It will be appreciated that in various embodiments, the substrate may be changed to the first Ti reactant and/or the second Ti reactant in each of the first cycles 408A based on various considerations including susceptibility to steric effects of the precursors. The frequency and repetition rate of the exposure of an N precursor and the exposure to the second Ti reactant and/or the second N precursor in each of the second cycles 408B to achieve the desired thickness and stoichiometry.

According to various embodiments, non-limiting examples of first and second Ti precursors that may be the same or different for forming the first and second portions of the TiN layer according to embodiments include titanium tetrachloride (TiCl ₄ ), Tetrakis(dimethylamino)titanium (TDMAT) or tetrakis(diethylamido)titanium (TDEAT). It may be advantageous to have the same precursor for the first and second portions of TiN, eg, lower cost and/or easier programming. However, it may be advantageous to have different precursors for the first and second portions of TiN, eg for different deposition characteristics or film qualities.

According to various embodiments, non-limiting examples of first and second N precursors that may be the same or different for forming the first and second portions of the TiN layer according to embodiments include ammonia (NH ₃ ), hydrazine ( N ₂ H ₄ ) or methylhydrazine (CH ₃ (NH)NH ₂ , “MMH”). It may be advantageous to have the same precursor for the first and second portions of TiN, eg, lower cost and/or easier programming. However, it may be advantageous to have different precursors for the first and second portions of TiN, eg for different deposition characteristics or film qualities.

According to various embodiments, non-limiting examples of inert gases used for purge may include nitrogen N ₂ or noble gases such as Ar or He.

According to an embodiment, when at 350 ^° C to 800 ^° C, 450 ^° C to 750 ^° C, 500 ^° C to 700 ^° C, 550 ^° C to 650 ^° C or defined by any one of these values When one or both of the first portion 370 and the second portion 380 ( FIG. 3B ) comprising a thin film of TiN are formed at substrate temperatures in the range (e.g., about 600 ^° C.), various technical advantages and advantages described herein can be realized. benefit. Keeping the temperature the same during the growth of the first portion 370 and the second portion 380 can be beneficial for throughput and ease of program control since temperature adjustments during the process can take a long time.

In various embodiments, the exposure time or pulse time of each of the first and second Ti precursors and the first and second N precursors can be in the range of about 0.1 seconds to 1 second, 1 second to 10 seconds, 10 seconds to 30 seconds, 30 seconds to 60 seconds, or may be a duration within a range defined by any of these values.

Advantageously, when forming the TiN layer using an atomic layer deposition method according to various embodiments in which the substrate is exposed to a plurality of cycles with different corresponding precursor exposure pressures, one of surface roughness and resistivity or Both are substantially reduced to conventional TiN films comprising TiN films formed using other ALD procedures with a single pressure set point. When deposited, a thin film comprising TiN formed according to the methods described herein and having the thicknesses described above and the thickness ratio between the first portion 370 and the second portion 380 ( FIG. 3B ) can have a thickness based on the average thickness of the film. Root mean square (RMS) surface roughness of 3%, 4%, 5%, 6%, 7%, 8% and 9% or a value within the range defined by any of these values. Alternatively, a thin film comprising TiN having the aforementioned thickness and thickness ratio between the first portion 370 and the second portion 380 ( FIG. 3B ) may have a thickness of less than 2.5 nm, 2 nm, 1.5 nm, 1.0 nm, RMS surface roughness value of 0.5 nm or a value within the range defined by any of these values.

When deposited, a thin film comprising TiN formed according to the methods described herein and having the aforementioned thicknesses and thickness ratios between first portion 370 and second portion 380 ( FIG. 3B ) can have <70 μΩ-cm, 70 μΩ -cm to 100 μΩ-cm, 100 μΩ-cm to 130 μΩ-cm, 130 μΩ-cm to 160 μΩ-cm, 160 μΩ-cm to 190 μΩ-cm, 190 μΩ-cm to 220 μΩ-cm, 220 μΩ -cm to 250 μΩ-cm, 250 μΩ-cm to 280 μΩ-cm, 280 μΩ-cm to 310 μΩ-cm, or greater than 310 μΩ-cm, or within a range defined by any of these values ( For example, a resistivity of a value less than about 200 μΩ-cm).

In addition to reducing surface roughness and resistivity, thin films comprising TiN formed according to the methods disclosed herein are also highly conformal when deposited in high aspect ratio structures. In the context of high aspect ratio structures, one measure of conformality is referred to herein as step coverage. For example, the high aspect ratio structures may be vias, holes, trenches, cavities, or similar structures. By way of illustrative example, FIG. 5 schematically depicts a semiconductor structure 500 having an example high aspect ratio structure 516 formed therein to illustrate defining and/or measuring the retention of thin films formed on the high aspect ratio structure. Some example measures of formality. The depicted high aspect ratio structure 516 is lined with a TiN layer 512 having different thicknesses at different portions thereof. As described herein, a high aspect ratio structure has an aspect ratio exceeding 1, eg, defined as the ratio of the depth or height (H) of the high aspect ratio structure 516 divided by the width (W) at the open area. In the depicted example, the high aspect ratio structure 516 is formed via a via through a dielectric layer 508 (eg, an interlayer dielectric (ILD) layer) formed on the semiconductor substrate 504 such that the high aspect ratio structure The bottom surface of 516 exposes the underlying semiconductor 504 . The TiN layer 512 can coat different surfaces of the high aspect ratio structure 516 with different thicknesses. As described herein, one metric used to define or measure the conformality of films formed at high aspect ratios is called step coverage. Step coverage can be defined as the ratio between the thickness of a film below or at the bottom region of a high aspect ratio structure and the thickness of the film above or at the top region of the high aspect ratio structure. The upper or top region may be a region of the high aspect ratio structure at a relatively small depth (eg, at 0 to 10% or 0 to 25% of H measured from the top of the opening). The lower or bottom region may be the region of the high aspect ratio structure at a relatively greater depth (eg, at 90% to 100% or 75% to 100% of H measured from the top of the opening). In some high aspect ratio structures, it may be defined by the ratio of the thickness of film 512A formed at the bottom surface of the high aspect ratio structure to the thickness of film 512C formed above or at the top sidewall surface of the high aspect ratio structure or Measure ladder coverage. However, it will be appreciated that some high aspect ratio structures may not have a well-defined bottom surface or have a bottom surface with a small radius of curvature. In such structures, the ratio of the thickness of the film 512B formed under the high aspect ratio structure or at the bottom sidewall surface to the thickness of the film 512C formed above the high aspect ratio structure or at the top sidewall surface can be adjusted. Consistently define or measure ladder coverage.

As described above, thin films comprising TiN formed according to the methods disclosed herein result in reduced surface roughness and resistivity, while also providing high conformality in high aspect ratio structures. According to various embodiments, it may be covered in steps exceeding 70%, 80%, 90%, 95% as defined herein, or having a value within a range defined by any of these values, according to embodiments Conformally coating with a TiN film has a high aspect ratio of an aspect ratio exceeding 1, 2, 5, 10, 20, 50, 100, 200, or a value within a range defined by any of these values structure. Physical characterization of TiN formed by exposing substrates to multiple cycles with different corresponding precursor exposure pressures

FIG. 6 is a graph showing a total of 600 combined first cycles (e.g., nucleation phase) and second cycles (e.g., bulk deposition phase) to Ti and N at a relatively low chamber pressure of 0.5 Torr. The experimentally measured root mean square (RMS) surface roughness trend 604 and step coverage trend 608 as a function of the number of first cycles of exposure of the precursor. The second cycle of exposure to Ti and N precursors was at a relatively high chamber pressure of 5 Torr. The experimental data points in Fig. 6 were obtained from TiN films grown on _SiO2 -coated native Si substrates and TiN films formed in _SiO2 with an aspect ratio of about 40:1 for surface roughness measurements. The TiN film in the hole is obtained. The measured deposition rates for the first and second cycles were 0.28 Å/cycle and 0.38 Å/cycle, respectively. The experimental data is based on 0 first cycle (0 Å) / 600 second cycle (228 Å), 50 first cycle (14 Å) / 550 second cycle (209 Å), 200 first cycle (56 Å) / 400 second cycles (152 Å) and 600 first cycles (168 Å) / 0 second cycles (0 Å) on four different TiN films grown. The four TiN films have total thicknesses of about 228 Å, 223 Å, 208 Å, and 168 Å, respectively. As described above, the measured surface roughness values of the TiN films decreased as the relative number of first cycles comprising exposure at relatively lower pressures increased. Without being bound by any theory, this may be because lower growth rates tend to allow more surface diffusion, which tends to reduce surface roughness and promote layer-by-layer growth. Measured surface roughness values for films grown with 0 first cycle/600 second cycle, 50 first cycle/550 second cycle, and 200 first cycle/400 second cycle, respectively are about 21 Å, 17.5 Å and 12.5 Å, corresponding to about 9%, 8% and 6% on the basis of the total thickness of the respective TiN films. In addition, as discussed above, the measured step coverage of the TiN film for the film grown with 0 first cycle/600 second cycle relative to the film grown with 600 first cycle/0 second cycle Rate value is higher. Without being bound by any theory, this may be because higher pressure tends to allow more precursor to reach the bottom of the high aspect ratio via, which tends to improve step coverage. Surprisingly, however, the inventors have found that up to about 50 first cycles (8% of the total number of cycles), increasing the number of first cycles actually improves step coverage. Thus, according to some embodiments, forming the first portion of the TiN film includes alternately exposing the semiconductor substrate to a first Ti precursor and to a first N precursor each at a relatively low exposure pressure of less than about 3 Torr. 1 to 50 cycles of exposure.

7A-9 illustrate the growth of TiN films grown by exposing substrates to cycles with the same precursor exposure pressure and by exposing the substrate to a plurality of cycles with different corresponding precursor exposure pressures, according to embodiments. Further experimental comparison between as-grown TiN films. 7A is a cross-sectional transmission electron microscope of a TiN layer lined high aspect ratio via formed by an atomic layer deposition method in which the substrate is exposed to an ALD cycle at the same precursor exposure pressure corresponding to the second cycle. photo. 7B and 7C are transmission electron micrographs (TEM) of TiN films grown using only the second cycle of exposure to Ti and N precursors at a relatively high chamber pressure of 5 Torr. The TEM images were taken at regions above ( FIG. 7B ) and below ( FIG. 7C ) the via formed in SiO ₂ with an aspect ratio of about 40:1. In contrast, FIGS. 8A and 8B are first and second cycles of exposure to Ti and N precursors using relatively low (0.5 Torr) and high (5 Torr) chamber pressures, according to embodiments. Transmission electron micrographs (TEM) of TiN films grown in combination with . The TEM images were taken at regions above (FIG. 8A) and below (FIG. 8B) the via formed in _SiO2 with an aspect ratio of about 40:1. FIG. 9 is a graph showing the measured step coverage 904 measured from the TEM micrographs shown in FIGS. 7A-7C and measured from the TEM micrographs shown in FIGS. 8A-8B A graph of experimental statistical comparisons between measured ladder coverage 908. The data points in FIG. 9 represent ratios taken from different locations in the area below the via and different locations in the area above the via. Although not readily apparent from the TEM images, the statistics in Figure 9 more clearly show the higher median step coverage of 93% for the TiN film deposited according to the examples and 87% for the TiN film deposited using a single exposure pressure. Median ladder coverage. In addition, the statistical distribution of measured step coverage for TiN films deposited according to the examples was substantially smaller than the statistical distribution of measured step coverage for TiN films deposited using a single exposure pressure, indicating that the film roughness of the latter is significant higher. Atomic Layer Deposition of TiN Thin Films with Increased (111) Crystal Texture

For specific applications of TiN thin films (e.g., DRAM capacitor electrodes), to meet the increasing demand for positive scaling, TiN films may need to be very thin (e.g., less than 30 nm) while meeting stringent requirements for electrical and mechanical properties. combination. For example, in addition to low resistivity and high conformality as discussed above, some TiN films are also required to simultaneously satisfy a combination of stringent mechanical properties (e.g., relatively high density, hardness, and modulus) in order to reduce the risk of integration failure .

TiN films grown by atomic layer deposition can have grains with different crystallographic orientations including (111) and (200) orientations at the surface, as well as other orientations. The inventors have discovered that TiN thin films textured to have a specific crystalline texture can have superior mechanical properties in addition to the desired low resistivity and conformality as described above. In particular, ultrathin TiN films with relatively high (111) crystalline texture can have relatively high density, hardness and modulus. In addition, the increased (111) crystalline texture can reduce columnar growth, thereby providing superior diffusion barrier properties. Without wishing to be bound by any theory, these favorable properties of TiN thin films with relatively high (111) crystalline texture can be related to the highest surface atomic packing density in the direction parallel to the growth surface and the grain boundaries that favor superior bulk properties. One of the configurations is associated. The present inventors have further discovered that, as described herein, the texture of TiN thin films can be controlled by controlling the specific conditions of the periodic vapor deposition cycles. In particular, the inventors have discovered that periodic vapor deposition cycles in which the substrate is subjected to a relatively high flow rate of N precursor can cause TiN thin films to grow with a relatively high (111) crystalline texture, as described herein .

11 schematically depicts a flowchart of an atomic layer deposition method 1100 for forming a TiN layer with a relatively high (111) crystalline texture by exposing a substrate to a relatively high N precursor flow rate, according to an embodiment. Method 1100 includes providing 1110 a semiconductor substrate. Additionally, the method 1100 includes exposing 1120 the semiconductor substrate to one or more periodic vapor deposition cycles each comprising exposure to the Ti precursor at the Ti precursor flow rate and exposure to the N precursor at the N precursor flow rate. . Method 1100 operates by exposing 1120 a semiconductor substrate to which the ratio of N precursor flow rate to Ti precursor flow rate (N/Ti flow ratio) and/or the flow rate of N precursor is substantially higher than conventional methods One or more periodic vapor deposition cycles form a TiN film with a relatively high (111) crystalline texture. According to various embodiments, the ratio of N precursor flow rate to Ti precursor flow rate (N/Ti flow ratio) exceeds 3. According to various embodiments, the N precursor flow rate exceeds 500 sccm. It will be appreciated that exposing 1120 and forming 1130 are not necessarily ordered as shown. Various implementations of the method 1100 are described herein.

Providing 1110 the semiconductor substrate may be similar to providing 310 the semiconductor substrate according to the various embodiments described above with respect to FIGS. 3A and 3B , details of which are not repeated herein for the sake of brevity. For example, the substrate may be patterned or unpatterned, and may have one or both of insulating and conductive surfaces as described above.

Exposing 1120 the semiconductor substrate may be similar to exposing the semiconductor substrate to one or more first or second thermal ALD cycles as described above with respect to FIGS. 3A , 3B and 4 and is not repeated here for brevity. its details. For example, the exposure to the Ti precursor at the Ti precursor flow rate may be based on the exposure 404 (FIG. 4) to the first Ti precursor or the exposure 412 (FIG. 4) to the second Ti precursor. Similarly, the exposure to the N precursor at the N precursor flow rate may be in accordance with the exposure 408 (FIG. 4) to the first N precursor or the exposure 416 (FIG. 4) to the second N precursor. For brevity, the details of these procedures are not repeated herein. According to various embodiments, exposing 1120 results in the formation of a TiN film with a high (111) crystalline texture, as described herein.

According to various embodiments, the Ti precursor and the N precursor may be any of the precursors described above. For example, the Ti precursor may be titanium tetrachloride (TiCl ₄ ) and the N precursor may be ammonia (NH ₃ ).

Various other process parameters including substrate temperature, chamber pressure, and exposure time can be based on the various process parameters described above, the details of which are not repeated herein for the sake of brevity.

According to an embodiment, exposing 1120 is such that the ratio of N precursor flow rate to Ti precursor flow rate (N/Ti flow ratio) exceeds 2. The ratio may exceed 2, 3, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, or have a value within a range defined by any of these values.

According to an embodiment, exposing 1120 is such that the N precursor flow rate exceeds 200 sccm. For example, the N precursor flow rate can exceed 200 sccm, 500 sccm, 1000 sccm, 2000 sccm, 3000 sccm, 4000 sccm, 5000 sccm, 6000 sccm, 7000 sccm, 8000 sccm, 9000 sccm, 10000 sccm, or with A value within the range defined by any of these values.

According to an embodiment, the exposure 1120 is such that the Ti precursor flow rate exceeds 100 sccm but does not exceed the N precursor flow rate according to the N/Ti flow ratio described above. For example, the Ti precursor flow rate may exceed 100 sccm, 200 sccm, 500 sccm, 1000 sccm, 2000 sccm, 3000 sccm, 4000 sccm, 5000 sccm, or have a range defined by any of these values value.

Figure 12A shows the experimental X-ray diffraction spectrum of the resulting TiN thin film with relatively high (111) crystalline texture according to an embodiment. X-ray diffraction spectra were taken from Examples 1 to 4 shown in Table 1 below. FIG. 12B shows the peak height of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the peak value of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN obtained from the X-ray diffraction spectrum of FIG. 12A Graph of the experimental ratio of height. The depicted TiN thin film is shown as an example only, and the embodiments are not limited thereto. According to an embodiment, the N precursor flow rate range and the Ti precursor flow rate range enable TiN films to have a relatively high (111) crystalline texture relative to a comparable film (e.g., TiN of similar thickness) obtained by Exposing the semiconductor substrate to exposures each including to a different Ti precursor flow rate range outside the Ti precursor flow rate range described above and to a different N precursor flow outside the N precursor flow rate range described above Formed by periodic vapor deposition cycles of exposure over a range of rates. The degree of increased (111) texture can be measured using, for example, X-ray diffraction. For example, the relative intensities of different X-ray peaks can provide at least a semi-quantitative indication of the degree of texturing. The TiN thin film formed according to the embodiment advantageously has a relatively high (111) crystal texture, so that the X-ray spectrum of the thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation and the peak height or intensity corresponding to the (200) crystal orientation. The ratio of the peak height or intensity of the X-ray diffraction peak exceeding 0.4. For example, this ratio may exceed 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, or a value within the range defined by any of these values. Selected experimental precursor flow conditions and corresponding ratio measurements are summarized in Table 1.

13 is a graph of experimental thickness and resistivity measurements of TiN films with relatively high (111) crystalline texture, according to an embodiment. For Examples 1 to 4 listed in Table 1, increasing the N/Ti flow ratio decreased thickness for the same number of cycles. Unexpectedly, unlike conventional methods, increasing the N/Ti flow ratio (which in turn reduces the thickness) reduces the resistivity of TiN thin films. Prior to the present invention, decreasing thickness was associated with increasing resistivity associated with relatively higher amounts of chlorine in relatively thin TiN films formed from _TiCl4 . The depicted TiN thin film is shown as an example only, and the embodiments are not limited thereto. Advantageously, TiN films formed according to embodiments have a resistivity of less than about 200 μΩ-cm, or any of the values described above. The selected experimental precursor flow conditions and corresponding measurements of thickness and resistivity are summarized in Table 1 . Table 1 example TiCl ₄ flow rate (sccm) NH ₃ flow rate (sccm) NH ₃ /TiCl ₄ flow rate ratio Thickness (Å) Resistivity (μΩcm) Sheet Resistance (Ω/sq) (111) X-ray peak/(200) X-ray peak ratio 1 140 500 3.6 268 159 59.3 0.43 2 140 1000 7.1 265 145 54.5 0.56 3 140 2000 14.3 261 136 52.2 0.75 4 140 4000 28.6 261 129 49.4 1.39

14 is a graph of experimental hardness and modulus measurements of TiN thin films having substantially the same thickness and a preferential (111) crystalline texture, according to an embodiment. 15 is a graph of experimental hardness measurements for two different thicknesses of TiN thin films with relatively high (111) crystalline texture, according to an embodiment. According to an embodiment, increasing the N/Ti flow ratio (which in turn reduces the thickness) increases the Young's modulus and hardness of the TiN film. The depicted TiN thin film is shown as an example only, and the embodiments are not limited thereto. Advantageously, the hardness of the TiN film formed according to the embodiments exceeds 6 GPa. For example, hardness may exceed 6 GPa, 10 GPa, 14 GPa, 18 GPa, 22 GPa, 25 GPa, or have a value within a range defined by any of these values. Advantageously, the elasticity or Young's modulus of TiN films formed according to the embodiments exceeds 150 GPa. For example, the Young's modulus may exceed 150 GPa, 170 GPa, 190 GPa, 210 GPa, 230 GPa, 250 GPa, 270 GPa, 300 GPa, or have a value within the range defined by any of these values .

According to the methods described herein, reducing the deposition pressure increases the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN. Strength ratio. This is illustrated in FIG. 16 , which shows experimental X-ray spectra of TiN thin films formed under different exposure pressures and having a preferential (111 ) crystalline texture, according to an embodiment. The depicted TiN thin film is shown as an example only, and the embodiments are not limited thereto. Specifically, X-ray diffraction profiles were taken for TiN films with the same thickness but formed at two different exposure pressures (ie, 5 Torr and 3 Torr). The results show that lower pressure can lead to further increase of (111) crystalline texture. However, the inventors have recognized that, in some circumstances, lower exposure pressures can result in stepped coverage of damage. Therefore, in such circumstances, according to an embodiment, after forming 1130 ( FIG. 11 ) a TiN thin film having a relatively high (111) crystalline texture, the method 1100 ( FIG. 11 ) may further comprise exposing the semiconductor substrate to various one or more second periodic vapor deposition cycles comprising exposure to a second Ti precursor and exposure to a second N precursor to form a second TiN thin film on the TiN thin film, wherein relative to the one or more first Corresponding exposure to one or both of the Ti precursor and the N precursor during one periodic vapor deposition cycle, to the second Ti precursor and the first Ti precursor during the one or more second periodic vapor deposition cycles Exposure to one or both of the two N precursors is at higher pressure. Other exposure conditions corresponding to forming 1130 ( FIG. 11 ) the TiN film and forming the second TiN film may be according to any of the exposure conditions described above with respect to FIGS. 3A , 3B and 4 .

17 shows the chlorine concentration depth profile of a TiN thin film with increased (111) crystalline texture according to an embodiment. Depth profiles were obtained using secondary ion mass spectrometry. The measured films correspond to Examples 1 to 4 listed in Table 1. As described above, increasing the N/Ti flow ratio reduces thickness for the same number of cycles. Unexpectedly, unlike conventional methods, increasing the N/Ti flow ratio (which in turn reduces the thickness) reduces the resistivity of TiN thin films. Figure 17 shows that the unexpected trend of decreasing resistivity with decreasing thickness correlates with decreasing chlorine concentration. For the range of N/Ti flow ratios covered by Examples 1 to 4, the amount of chlorine can be reduced by more than 50%. For example, at about 10 nm, chlorine concentrations were measured as 7.2x10 ²⁰ /cm ³ , 6.1x10 ²⁰ /cm ³ , 5.1x10 ²⁰ /cm ³ , and 3.5x10 ²⁰ /cm ³ for Examples 1 to 4, respectively. Prior to the present invention, reduced thickness was associated with increased chlorine content, which was associated with relatively higher resistivity. Atomic Layer Deposition of Bilayer TiN Thin Films with Increased (111) Crystalline Texture

As described above, a high N/Ti flow ratio and/or low pressure can increase the (111) texture of the resulting TiN film. However, high N/Ti flow ratios can result in relatively low step coverage in a manner similar to that described above for low pressure deposited TiN films. To compensate, it may be desirable to have a bilayer procedure where a second TiN film is grown on a first TiN film with a high (111) texture.

According to these embodiments, the method includes exposing the semiconductor substrate to one or more periodic gases each comprising exposure to the Ti precursor at a Ti precursor flow rate and exposure to the N precursor at a N precursor flow rate. phase deposition cycle to form a TiN thin film on the semiconductor substrate. Additionally, the method includes exposing the semiconductor substrate to one or more of exposure to the second Ti precursor at a second Ti precursor flow rate and exposure to the second N precursor at a second N precursor flow rate, each comprising: A second periodic vapor deposition cycle is used to form a second TiN thin film on the TiN thin film. The method makes one or both of the TiN thin film and the second TiN thin film have a preferential (111) crystal texture, so that the X-ray spectrum of one or both of the TiN thin film and the second TiN thin film has a (111) crystal texture corresponding to TiN. The ratio of the peak height or intensity of the X-ray diffraction peak of the orientation to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN exceeds 0.4.

According to some other embodiments, a method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process includes exposing a semiconductor substrate to a first Ti precursor at a first Ti precursor flow rate. A first TiN thin film is formed on the semiconductor substrate at a first pressure by one or more first periodic vapor deposition cycles of exposure to a precursor and exposure to the first N precursor at a first N precursor flow rate. The first TiN thin film has a crystalline texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the X-ray corresponding to the (200) crystal orientation of TiN The ratio of the peak height or intensity of diffraction peaks exceeding 0.4. Additionally, the method includes exposing the semiconductor substrate to one of exposure to a second Ti precursor at a second Ti precursor flow rate and exposure to a second N precursor at a second N precursor flow rate by exposing the semiconductor substrate to or a plurality of second periodic vapor deposition cycles to form a second TiN film on the first TiN film at a second pressure higher than the first pressure.

Advantageously, the second TiN film grown on the TiN film can benefit from the high (111) texture of the underlying first TiN film. Under these circumstances, the second TiN film may also have a relatively high (111) texture, despite the fact that if grown on another surface that does not have the (111) TiN texture of the underlying first TiN film, the second TiN films may not have a relatively high (111) texture. For example, if grown on a different surface (e.g., a material other than TiN or TiN that does not have a relatively high (111) texture), such as an insulating film such as SiO ₂ , Si, or other materials, the second TiN film may not Has a relatively high (111) texture. For example, if grown on another surface, the second TiN layer can have a crystalline texture such that the X-ray spectrum of the TiN thin film has a peak height or intensity corresponding to the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and corresponding to The ratio of peak heights or intensities of the X-ray diffraction peaks of the (200) crystal orientation of TiN to substantially less than 0.4 (eg, 0.3, 0.2, 0.1, or a value within a range defined by any of these values). This is because the textured surface of the underlying TiN film can be used as a template for the second TiN film so that the second TiN film can be formed under conditions of increased step coverage (e.g., as described above for the various two-step deposition procedures). under high pressure) to grow.

For example, the second TiN film can be formed at high pressures as described above (eg, greater than 3 Torr or 5 Torr), eg, according to the various two-step procedures described with respect to FIGS. 3A and 3B . For example, by texturing the first TiN film to have a relatively high (111) orientation, initial film growth can proceed substantially in a (111) texture-favorable mode, which advantageously results in the improved mechanical properties and resistivity. On the other hand, by subsequently exposing the substrate to Ti and/or N precursors at a relatively high pressure (e.g., greater than 3 Torr) during deposition of the second portion of the film, a later portion of the film or a second TiN film can be Advantageously, with respect to a first TiN thin film having a relatively high (111) texture or with respect to a TiN precursor by exposing the substrate to a Ti and/or N precursor at a relatively low pressure (e.g., less than 3 Torr or less than 1 Torr) TiN films deposited in bulk can grow with higher conformality or step coverage.

In addition, since the first portion of the TiN film has a relatively high (111) texture, the second portion of the film can continue to grow in a layer-by-layer manner using the first portion as a template. The second TiN film may have a lower or comparable (111) texture relative to the underlying first TiN film.

As a final result, when deposited on a particular surface (e.g., a surface including a non-metallic surface), it involves depositing a relatively highly (111) textured first TiN film followed by a second TiN film according to the methods disclosed herein. The thin films of the first and second portions deposited as thin films advantageously have a combination of surface roughness and conformality superior to thin film layers formed on the same surface using a single step. Alternatively or additionally, due in part to the improved smoothness and conformality, the thin films have relatively lower resistivity compared to TiN layers formed by some prior methods. application

Thin films comprising TiN formed using different exposure pressures according to various embodiments disclosed herein can be used in a variety of applications, especially where substrates include relatively high aspect ratios that can benefit from the various advantageous properties of the TiN layer as disclosed herein. than in the case of structures and/or non-metallic surfaces. Exemplary applications include aspect ratios (e.g., defined as depth divided by Deposition in vias, holes, trenches, cavities, or similar structures.

By way of example, FIG. 10 schematically illustrates in the context of a diffusion barrier for a contact structure (eg source or drain contact) formed on an active semiconductor substrate region that may be heavily doped. application. Depicted is a portion of a semiconductor device 1000 comprising a substrate 1004 on which a dielectric layer 1008 (eg, an interlayer or intermetal dielectric (ILD) layer) comprising a dielectric material such as an oxide or nitride is formed superior. To form contacts to various regions of the substrate 1004 , including various doped regions such as source and drain regions, vias or trenches may be formed through the dielectric layer 1008 . The via or the trench can expose various non-metallic surfaces, for example, the exposed bottom surface of the via including the substrate surface (eg, a silicon substrate surface), and dielectric sidewalls. A first portion (corresponding to first portion 370 in FIG. 3B ) of a TiN layer formed according to embodiments described herein may then be conformally coated with a second portion (corresponding to second portion 380 in FIG. 3B ). Bottom surface and side surface of through hole. According to various embodiments disclosed herein, the conformal first portion may first be formed directly on the inner surface of the via, followed by the formation of the conformal second TiN layer. Thereafter, the lined via hole may be filled with a metal (eg, W, Al, or Cu) to form a contact plug 1016 . For example, vias can be filled with tungsten by CVD using, for example, WF ₆ .

Barrier layer 1012 formed according to embodiments may be advantageous for a variety of reasons. In particular, due to the conformal nature of the barrier layer 1012 formed by ALD, the propensity for pinching off during subsequent metal fill processes can be substantially reduced. In addition, as described above, the barrier layer 1012 can provide an effective barrier to material transport across it, for example, outdiffusion of dopants (B, P) from the substrate 1004, and reactants from the contact plug formation process, etch Agents and metals (eg, F, Cl, W or Cu) diffuse inwardly. The barrier effect can be enhanced by reduced surface roughness and increased step coverage. Furthermore, as described above, the layer-by-layer growth mode can reduce the overall contact resistance of the barrier layer 1012 . Furthermore, due to the reduced film roughness, a relatively thinner barrier layer 1012 can be formed while still fulfilling its intended barrier function, resulting in a further reduction in contact resistance.

Other applications of TiN layers formed according to various embodiments disclosed herein include, to name a few, conductive structures (e.g., buried electrodes or lines), electrodes (e.g., DRAM capacitor electrodes) formed in recessed substrates, or gate electrodes), metallization barriers for higher metal levels (e.g. barriers in vias/trenches for Cu contacts/lines), high aspect ratio vertical rod electrodes or for 3D memory Body vias and through-silicon vias (TSVs). Exemplary Embodiment I : 1. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: One or more periodic vapor deposition cycles of exposure to Ti precursor and exposure to N precursor at a flow rate of N precursor to N precursor to form a TiN thin film on the semiconductor substrate, wherein the N precursor flow rate is the same as that of the Ti precursor The ratio of volume flow rate exceeds 3. 2. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: exposing a semiconductor substrate to a Ti precursor at a Ti precursor flow rate and A TiN film is formed on the semiconductor substrate by one or more periodic vapor deposition cycles of exposure to the first N precursor at a first N precursor flow rate, wherein the N precursor flow rate exceeds 200 sccm. 3. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: exposing a semiconductor substrate to a Ti precursor flow within a range of Ti precursor flow rates TiN film is formed on the semiconductor substrate by one or more periodic vapor deposition cycles of exposure to the Ti precursor at a flow rate of the N precursor at a flow rate of the N precursor to the N precursor, wherein The N precursor flow rate range and the Ti precursor flow rate range make the TiN thin film relative to the Ti precursor flow rate range by exposing the semiconductor substrate to different Ti precursor flow rate ranges each including to outside the Ti precursor flow rate range. Another TiN film formed by periodic vapor deposition cycles of exposure to the Ti precursor and exposure to the N precursor in a different N precursor flow rate range than the N precursor flow rate range has priority ( 111) Crystalline textures. 4. The method of any one of the above embodiments, wherein the ratio of the N precursor flow rate to the Ti precursor flow rate is 2-100. 5. The method according to any one of the above embodiments, wherein the N precursor flow rate is 200 sccm to 10,000 sccm. 6. The method according to any one of the above embodiments, wherein the Ti precursor flow rate is 100 sccm to 5000 sccm. 7. The method according to any one of the above embodiments, wherein the TiN thin film has a preferential (111) crystal texture, so that the X-ray spectrum of the TiN thin film has a peak height corresponding to an X-ray diffraction peak of the (111) crystal orientation or The ratio of the intensity to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation exceeds 0.4. 8. The method of any one of the above embodiments, wherein the TiN thin film has a hardness exceeding 6 GPa. 9. The method of any one of the preceding embodiments, wherein the TiN thin film has a Young's modulus exceeding 150 GPa. 10. The method of any one of the above embodiments, further comprising: exposing the semiconductor substrate to one or more second Ti precursors each including exposure to a second Ti precursor and exposure to a second N precursor. periodic vapor deposition cycles to form a second TiN film on the TiN film, wherein relative to one or both of the Ti precursor and the N precursor during the one or more periodic vapor deposition cycles Corresponding to exposure, exposure to one or both of the second Ti precursor and the second N precursor during the one or more second periodic vapor deposition cycles is at a higher pressure. 11. The method of embodiment 10, wherein the exposure to one or both of the Ti precursor and the N precursor during the one or more periodic vapor deposition cycles is a reaction at less than about 5 Torr under pressure, and wherein the exposure to one or both of the second Ti precursor and the second N precursor during the one or more second periodic vapor deposition cycles is greater than about 5 Torr under the reactor pressure. 12. The method of embodiment 10 or 11, wherein relative to the corresponding exposure to each of the Ti precursor and the N precursor during the one or more periodic vapor deposition cycles, during the one or more periodic vapor deposition cycles, The exposure to each of the second Ti precursor and the second N precursor during a second periodic vapor deposition cycle is at a higher pressure. 13. The method of any one of embodiments 10 to 12, wherein forming the TiN thin film comprises exposing the semiconductor substrate to the Ti precursor and exposing the N precursor to the periodic vapor deposition cycles Depositing at a first deposition rate each of less than 0.3 Å, and wherein forming the second TiN thin film includes the first deposition rates including exposure of the semiconductor substrate to the second Ti precursor and exposure to the second N precursor Depositing is performed at a second deposition rate greater than 0.3 Å for each of the two periodic vapor deposition cycles. 14. The method of any one of the preceding embodiments, wherein the root mean square surface roughness of the film is less than about 8% of the thickness of the film. 15. The method of any one of embodiments 10 to 14, wherein forming the TiN thin film and the second TiN thin film comprises depositing by thermal periodic vapor deposition. 16. The method of any one of embodiments 10 to 15, wherein forming the TiN thin film comprises directly exposing one or both of a semiconductor surface and an insulator surface to the one or more periodic vapor deposition cycles. 17. The method of any one of embodiments 10 to 16, wherein forming one or both of the TiN thin film and the second TiN thin film comprises growing in a layer-by-layer growth mode. 18. The method of any one of embodiments 10 to 17, wherein forming the TiN thin film comprises alternately exposing the semiconductor substrate to 1 to 50 periodic vapor deposition cycles. 19. The method of any one of embodiments 10 to 18, wherein forming the TiN thin film and the second TiN thin film comprises forming at a temperature between 400 ^° C and 600 ^° C. 20. The method of any one of the preceding embodiments, wherein the semiconductor substrate comprises a trench or via comprising an inner surface comprising non-metallic sidewall surfaces in the trench or via having an aspect ratio exceeding 1, and wherein forming the film includes conformally lining the inner surface, wherein forming the film over 25% of the height of the trench or the via and above 25% of the height of the trench or the via The thickness ratio exceeds 0.9. 21. The method of any one of the preceding embodiments, wherein the resistivity of the thin film is less than about 200 μΩ-cm. 22. The method of any one of embodiments 10 to 21, wherein the Ti precursor system is the same as the second Ti precursor and the N precursor system is the same as the second N precursor. 23. The method of any one of embodiments 1 to 9, comprising: providing the semiconductor substrate comprising trenches or vias having an aspect ratio exceeding 1; by exposing the semiconductor substrate to the one or more periodic vapor deposition to form the TiN thin film in the trench or the via; and further exposing the semiconductor substrate to each including exposure to a second Ti precursor and to Exposure of a second N precursor to one or more second periodic vapor deposition cycles to form a second TiN film on the TiN film, wherein relative to during the one or more second periodic vapor deposition cycles Corresponding exposure to one or both of the second Ti precursor and the second N precursor, to one or both of the Ti precursor and the N precursor during the one or more periodic vapor deposition cycles The exposure of the subjects was under different pressures. 24. The method of embodiment 23, wherein relative to the corresponding exposure to one or both of the Ti precursor and the N precursor during the one or more periodic vapor deposition cycles, during the one or more periodic vapor deposition cycles, Exposure to one or both of the second Ti precursor and the second N precursor during the second periodic vapor deposition cycle is at a higher pressure. 25. The method of embodiment 23 or 24, wherein relative to the corresponding exposure to one or both of the Ti precursor and the N precursor during the one or more periodic vapor deposition cycles, during the one or more periodic vapor deposition cycles, Exposure to one or both of the second Ti precursor and the second N precursor during the second plurality of periodic vapor deposition cycles is at 5 times or greater pressure. 26. The method of any one of embodiments 23 to 25, wherein forming the TiN thin film comprises alternately exposing the semiconductor substrate to 1 to 50 periodic vapor deposition cycles. 27. The method of any one of embodiments 23 to 26, wherein forming the TiN thin film comprises exposing the semiconductor substrate to a first number of the one or more periodic vapor deposition cycles, and wherein forming the second portion comprises The semiconductor substrate is exposed to a second number of second periodic vapor deposition cycles greater than twice the first number of the one or more periodic vapor deposition cycles. 28. The method of any one of embodiments 23 to 27, wherein the root mean square surface roughness of the film is less than about 8% of the thickness of the film. 29. The method of any one of embodiments 23 to 28, wherein forming the TiN layer comprises forming by thermal periodic vapor deposition at a temperature between 400 ^° C and 600 ^° C. 30. The method of any one of embodiments 23 to 29, wherein the trench or the via has an aspect ratio exceeding 5 and includes an inner surface that is a non-metallic sidewall surface, and wherein forming the film comprises conformally lining The inner surface, wherein the ratio of the thickness of the film formed on the lower 25% of the height of the trench or the through hole to the upper 25% of the height of the trench or the through hole exceeds 0.9. 31. The method of any one of embodiments 23 to 29, wherein the Ti precursor system is the same as the second Ti precursor and the N precursor system is the same as the second N precursor. 32. A semiconductor structure comprising: a semiconductor substrate comprising a non-metallic sidewall surface in a trench or via having an aspect ratio exceeding 5; and a thin film comprising TiN conformally lining the non-metallic sidewall surface , wherein the film has a preferential (111) crystalline texture such that the X-ray spectrum of the film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation and the X-ray diffraction peak corresponding to the (200) crystal orientation The peak height or intensity of the peaks exceeds the ratio of 0.4. 33. The semiconductor structure of embodiment 32, wherein the ratio exceeds 1.3. 34. The semiconductor structure of embodiments 32 and 33, wherein the thin film has a hardness exceeding 6 GPa. 35. The semiconductor structure of any one of embodiments 32 to 34, wherein the thin film has a Young's modulus in excess of 150 GPa. 36. The semiconductor structure of any one of embodiments 32 to 35, wherein the film is formed on the lower 25% of the height of the trench or the via and on the upper 25% of the height of the trench or the via The thickness ratio exceeds 0.9. 37. The semiconductor structure of any one of embodiments 32-36, wherein the trench or the via has an aspect ratio exceeding 10. 38. The semiconductor structure of any one of embodiments 32 to 37, wherein the root mean square surface roughness of the film formed on the non-metallic surface is less than about 8% based on the average thickness of the film. 39. The semiconductor structure of any one of embodiments 32-38, wherein the trench or the via has dielectric sidewalls. 40. The semiconductor structure of any one of embodiments 32 to 39, wherein the trench or the via has a bottom surface exposing the semiconductor material of the semiconductor substrate. 41. The semiconductor structure of any one of embodiments 32-40, wherein the thin film has a resistivity of less than about 200 μΩ-cm. 42. The semiconductor structure of any one of embodiments 32 to 41, wherein the trench or the via lined with the film is filled with a metal comprising tungsten. Exemplary Embodiment II : 1. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: One or more periodic vapor deposition cycles of exposure to Ti precursor and exposure to N precursor at a flow rate of N precursor to N precursor to form a TiN thin film on the semiconductor substrate, wherein the N precursor flow rate is the same as that of the Ti precursor The ratio of bulk flow rate (N/Ti flow ratio) exceeds 3, and wherein the method forms the TiN thin film with crystalline texture such that the X-ray spectrum of the TiN thin film has an X-ray orientation corresponding to the (111) crystal orientation of TiN The ratio of the peak height or intensity of the radiation peak to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN exceeds 0.4. 2. The method as in embodiment 1, wherein the N/Ti flow ratio is 3 to 100. 3. The method as in embodiment 1 or 2, wherein the method makes increasing the N/Ti flow ratio reduce the thickness of the TiN film. 4. The method according to any one of embodiments 1 to 3, wherein increasing the N/Ti flow ratio reduces the resistivity of the TiN thin film. 5. The method according to any one of embodiments 1 to 4, wherein the method causes increasing the N/Ti flow ratio to increase the Young's modulus of the TiN thin film. 6. The method of embodiment 5, wherein increasing the Young's modulus comprises increasing to a value exceeding 150 GPa. 7. The method according to any one of embodiments 1 to 6, wherein the method enables increasing the N/Ti flow ratio to increase the hardness of the TiN thin film. 8. The method of embodiment 7, wherein increasing the hardness comprises increasing to a value exceeding 6 GPa. 9. The method according to any one of embodiments 1 to 8, wherein increasing the N/Ti flow ratio reduces the chlorine content of the TiN film. 10. The method according to any one of embodiments 1 to 9, wherein the method reduces the deposition pressure and increases the peak height or the intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the intensity corresponding to that of TiN The peak height or the ratio of the intensity of the X-ray diffraction peak of the (200) crystal orientation. 11. The method according to any one of embodiments 1 to 10, wherein the N precursor flow rate is 500 sccm to 10,000 sccm. 12. The method according to any one of embodiments 1 to 11, wherein the Ti precursor flow rate is 100 sccm to 5000 sccm. 13. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: exposing a semiconductor substrate to a Ti precursor at a Ti precursor flow rate and forming a thin film of TiN on the semiconductor substrate at one or more periodic vapor deposition cycles of N precursor flow rate to N precursor exposure, wherein the N precursor flow rate exceeds 500 sccm, and wherein the method forms a The TiN thin film of crystalline texture makes the X-ray spectrum of the TiN thin film have the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN The peak height or intensity of the peaks exceeds the ratio of 0.4. 14. As in the method of embodiment 13, the ratio of the flow rate of the N precursor to the flow rate of the Ti precursor (N/Ti flow ratio) is 3-100. 15. The method of embodiment 14, wherein the method makes increasing the N/Ti flow ratio reduce the thickness of the TiN film. 16. The method of embodiment 15, wherein reducing the thickness reduces the resistivity of the TiN thin film. 17. The method of any one of embodiments 15-16, wherein reducing the thickness increases the Young's modulus of the TiN thin film. 18. The method of embodiment 17, wherein increasing the Young's modulus comprises increasing to a value exceeding 150 GPa. 19. The method of any one of embodiments 15 to 18, wherein reducing the thickness increases the hardness of the TiN film. 20. The method of embodiment 19, wherein increasing the hardness comprises increasing to a value exceeding 6 GPa. 21. The method of any one of embodiments 15 to 20, wherein reducing the thickness reduces the chlorine content of the TiN thin film. 22. The method according to any one of embodiments 13 to 21, wherein reducing the deposition pressure increases the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the difference between the (200) crystal orientation corresponding to TiN This ratio of the peak heights or intensities of X-ray diffraction peaks. 23. The method of any one of embodiments 13 to 22, wherein the N precursor flow rate is 500 sccm to 10,000 sccm. 24. The method of any one of embodiments 13 to 23, wherein the Ti precursor flow rate is 100 sccm to 5000 sccm. 25. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: exposing a semiconductor substrate to each comprising a first Ti precursor at a first Ti precursor flow rate body and one or more first periodic vapor deposition cycles of exposure to the first N precursor flow rate to the first N precursor to form a first TiN thin film on the semiconductor substrate, by making the semiconductor Exposing the substrate to one or more second periodic vapor depositions each comprising exposure to the second Ti precursor at a second Ti precursor flow rate and exposure to the second N precursor at a second N precursor flow rate cyclically forming a second TiN film on the first TiN film, wherein the method causes one or both of the first and second TiN films to have a preferential (111) crystalline texture such that the first and second TiN films The X-ray spectrum of one or both of the films has a peak height or intensity of an X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and a peak height or intensity of an X-ray diffraction peak corresponding to the (200) crystal orientation of TiN or The intensity exceeds the ratio of 0.4. 26. The method of embodiment 25, wherein relative to the corresponding exposure to one or both of the first Ti precursor and the first N precursor during the one or more first periodic vapor deposition cycles, Exposure to one or both of the second Ti precursor and the second N precursor during the one or more second periodic vapor deposition cycles is at a higher pressure. 27. The method of embodiment 26, the first ratio of the first N precursor flow rate to the first Ti precursor flow rate (first N/Ti flow ratio) and the second N precursor flow rate to the One or both of the second ratio of the second Ti precursor flow rate (second N/Ti flow ratio) is 3-100. 28. The method of embodiment 27, wherein the method causes increasing one or both of the first N/Ti flow ratio and the second N/Ti flow ratio to decrease one or both of the first and second TiN films The corresponding thickness of the two. 29. The method of embodiment 28, wherein reducing the corresponding thicknesses reduces the corresponding resistivity of one or both of the first and second TiN thin films. 30. The method of embodiment 28 or 29, wherein reducing the corresponding thicknesses increases the corresponding Young's modulus of one or both of the first and second TiN thin films. 31. The method of embodiment 30, wherein increasing the Young's moduli comprises increasing to a value exceeding 150 GPa. 32. The method of any one of embodiments 28 to 31, wherein decreasing the corresponding thicknesses increases the corresponding hardness values of the TiN thin film and the second TiN thin film. 33. The method of embodiment 32, wherein increasing the hardness values comprises increasing to a value exceeding 6 GPa. 34. The method of any one of embodiments 28 to 33, wherein reducing the corresponding thicknesses reduces the corresponding chlorine contents of the first and second TiN thin films. 35. The method according to any one of embodiments 25 to 34, wherein for the TiN thin film, the peak height or the intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN is the same as that corresponding to the TiN The ratio of the peak height or the intensity of the X-ray diffraction peak of (200) crystal orientation is higher relative to the ratio for the second TiN thin film. 36. The method of any one of embodiments 25 to 35, wherein during the one or more first periodic vapor deposition cycles, one or both of the first Ti precursor and the first N precursor The exposures are at a reactor pressure of less than about 5 Torr, and wherein during the one or more second periodic vapor deposition cycles to one or the second Ti precursor and the second N precursor Both such exposures were at reactor pressures greater than about 5 Torr. 37. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: exposing a semiconductor substrate to each comprising a first Ti precursor at a first Ti precursor flow rate forming a first TiN thin film on the semiconductor substrate at a first pressure by exposure of a precursor and one or more first periodic vapor deposition cycles of exposure to the first N precursor at a first N precursor flow rate, Wherein the first TiN thin film has a crystalline texture, so that the X-ray spectrum of the first TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) crystal orientation corresponding to TiN The ratio of the peak heights or intensities of the X-ray diffraction peaks exceeding 0.4; and by exposing the semiconductor substrate to each comprising exposure to the second Ti precursor at a second Ti precursor flow rate and a second N precursor flow One or more second periodic vapor deposition cycles of exposure to a second N precursor to form a second TiN film on the first TiN film at a second pressure higher than the first pressure. 38. The method of embodiment 37, wherein the second pressure is greater than 5 Torr. 39. The method according to embodiment 37 or 38, wherein the second TiN thin film has a crystalline texture such that the X-ray spectrum of the second TiN thin film has a peak height corresponding to the X-ray diffraction peak of the (111) crystal orientation of TiN or The ratio of the intensity to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN is lower than the corresponding ratio of the first TiN thin film. 40. The method of any one of embodiments 37 to 39, wherein at least a first ratio of the first N precursor flow rate to the first Ti precursor flow rate (first N/Ti flow ratio) is from 3 to 100. 41. The method of embodiment 40, wherein a second ratio of the second N precursor flow rate to the second Ti precursor flow rate (second N/Ti flow ratio) is lower than the first N/Ti flow rate Compare. 42. The method of embodiment 41, wherein the method causes increasing one or both of the first N/Ti flow ratio and the second N/Ti flow ratio to decrease one or both of the first and second TiN films The corresponding thickness of the two. 43. The method of embodiment 42, wherein reducing the corresponding thicknesses reduces the corresponding resistivity of one or both of the first and second TiN thin films. 44. The method of embodiment 42, wherein reducing the corresponding thicknesses increases the corresponding Young's modulus of one or both of the first and second TiN thin films. 45. The method of embodiment 44, wherein increasing the Young's moduli comprises increasing to a value exceeding 150 GPa. 46. The method of embodiment 42, wherein decreasing the corresponding thicknesses increases the corresponding hardness values of one or both of the first and second TiN thin films. 47. The method of embodiment 46, wherein increasing the hardness values comprises increasing to a value exceeding 6 GPa. 48. The method of embodiment 42, wherein reducing the corresponding thicknesses reduces the corresponding chlorine contents of the first and second TiN thin films. 49. The method of embodiment 37, wherein the first pressure is less than 5 Torr.

While the invention has been described herein with reference to specific embodiments, these embodiments are not intended to limit the invention and are set forth for illustrative purposes. Those skilled in the art will appreciate that modifications and improvements can be made without departing from the spirit and scope of the invention.

Such simple modifications and improvements of the various embodiments disclosed herein are within the scope of the invention, and furthermore, the specific scope of the invention will be defined by the accompanying claims.

In the foregoing, it will be appreciated that any feature of any one of the embodiments may be combined with or replaced by any other combination of features of any other of the embodiments.

Unless the context clearly requires otherwise, throughout the description and claims, the words "comprise/comprising", "include/including" and the like shall be construed as inclusive, and exclusive Or the opposite meaning of exhaustiveness; that is, interpreted as the meaning of "including but not limited to". As generally used herein, the word "coupled" refers to two or more elements that may be connected directly or through one or more intervening elements. Likewise, as generally used herein, the word "connected" refers to two or more elements that may be connected directly or through one or more intervening elements. Additionally, the words "herein," "above," "hereafter," and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. . Where the background content permits, the above [embodiment] words using singular or plural may also include plural or singular respectively. The word "or" in a list of two or more items includes all interpretations of the following words: any of the items in the list, all items in the list, and any combination of items.

Furthermore, unless expressly stated otherwise or otherwise understood within the context as used, conditional language (especially words such as "can/could", "might", "could ( "may", "e.g./for example", "such as" and the like) are generally intended to convey that some embodiments include and other embodiments do not include a particular feature, element, and/or state. Accordingly, this conditional language is generally not intended to imply that one or more embodiments require a feature, element, and/or state in any instance, or whether such feature, element, and/or state is included in any particular embodiment or in any particular implemented in the example.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel devices, methods, and systems described herein may be embodied in many other forms; furthermore, various omissions, forms, and forms of the methods and systems described herein may be made without departing from the spirit of the invention. Substitution and change. For example, although features are presented in a given configuration, alternative embodiments may perform similar functionality with different components and/or sensor topography, and some features may be deleted, moved, added, subdivided, combined, and/or modified. Each of these features can be implemented in a variety of different ways. Any suitable combination of the elements and acts of the various embodiments described above may be combined to provide further embodiments. The various features and procedures described above can be implemented independently of each other, or can be combined in various ways. All possible combinations and subcombinations of features of the invention are intended to fall within the scope of the invention.

100: Substrate 104: Precursor molecules/adsorbed molecules 108: layers 112: layer 116: Relatively smooth two-dimensional layer / stable two-dimensional layer 120: thin film structure 300: Atomic Layer Deposition Methods/Methods 310: step 320: Step 330: Step 350: Semiconductor Structure/Semiconductor Thin Film Structure 360: Substrate 370: Part One 380: Part Two 400A: First Cycle/First Atomic Layer Deposition (ALD) Cycle 400B: Second Cycle/Second Atomic Layer Deposition (ALD) Cycle 404: exposed 404A: Partial pressure rising state 404B: Main Exposure Status 404C: Partial pressure drop state 404P: total reaction chamber pressure/total pressure 408: exposed 408A: Partial pressure rising state 408B: Main Exposure Status 408C: Partial pressure drop state 408P: total reaction chamber pressure/total pressure 412: exposed 412A: Partial pressure rising state 412B: Main Exposure Status 412C: Partial pressure drop state 412P: total reaction chamber pressure/total pressure 416: exposed 416A: Partial pressure rising state 416B: Main Exposure Status 416C: Partial pressure drop state 416P: total reaction chamber pressure/total pressure 500: Semiconductor Structures 504: Semiconductor substrate / underlying semiconductor 508: dielectric layer 512: TiN layer 512A: Film 512B: Film 512C: Film 516: High aspect ratio structure 604: Root Mean Square (RMS) Surface Roughness Trend 608: Ladder Coverage Trends 904: Measured step coverage 908: Measured step coverage 1000: Semiconductor device 1004: Substrate 1008: dielectric layer 1012: barrier layer 1016: contact plug 1100: Atomic layer deposition methods/methods 1110:step 1120: Step 1130: Step

1A to 1D schematically illustrate the nucleation and growth mechanisms of thin films under different growth modes.

Figure 2 is a cross-sectional transmission electron micrograph of a TiN layer grown by thermal atomic layer deposition on an oxide-coated silicon substrate.

3A schematically depicts a flowchart of an atomic layer deposition method for forming a TiN layer by exposing a substrate to a plurality of cycles with different corresponding precursor exposure pressures, according to an embodiment.

3B schematically depicts a cross-sectional view of a semiconductor structure including a TiN layer formed by an atomic layer deposition method in which a substrate is exposed to a plurality of cycles with different corresponding precursor exposure pressures, according to an embodiment.

4 schematically depicts pressure traces for different cycles of an atomic layer deposition method in which a substrate is exposed to a plurality of cycles with different corresponding precursor exposure pressures, according to an embodiment.

Figure 5 schematically depicts a cross-sectional view of a via lined with a TiN layer having different thicknesses at different parts of the via.

6 shows experimentally measured surface roughness and steps as a function of thickness for a TiN layer formed by an atomic layer deposition method in which a substrate is exposed to multiple cycles with different corresponding precursor exposure pressures, according to an embodiment. A graph of reach trends.

7A is a cross-sectional transmission electron micrograph of a TiN layer lined high aspect ratio via formed by an atomic layer deposition method in which the substrate is exposed to ALD cycles performed at the same precursor exposure pressure.

Figure 7B is a cross-sectional transmission electron micrograph of the region above the high aspect ratio via shown in Figure 7A.

Figure 7C is a cross-sectional transmission electron micrograph of the region under the high aspect ratio via shown in Figure 7A.

8A is a high aspect ratio via similar to that shown in FIG. 7A by an atomic layer deposition method in which the substrate is exposed to multiple cycles with different corresponding precursor exposure pressures, according to an embodiment. Cross-sectional transmission electron micrograph of the TiN layer formed at the upper region.

8B is a cross-sectional transmission electron micrograph of a TiN layer formed at the region under the high aspect ratio via trench shown in FIG. 8A.

9 shows a statistical comparison of measured step coverage between TiN layers formed by ALD at a single exposure pressure and TiN layers formed by ALD at multiple exposure pressures, according to embodiments. chart.

10 schematically depicts a cross-sectional view of a TiN layer-lined via formed by an atomic layer deposition method in which a substrate is exposed to a plurality of cycles with different corresponding precursor exposure pressures, according to an embodiment.

11 schematically depicts a flowchart of an atomic layer deposition method for forming a TiN layer with increased (111) crystalline texture by exposing a substrate to a relatively high N precursor flow rate, according to an embodiment.

FIG. 12A shows experimental X-ray diffraction spectra of TiN thin films with different degrees of (111) crystalline texture according to embodiments.

FIG. 12B shows the peak height of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the peak value of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN obtained from the X-ray diffraction spectrum of FIG. 12A Graph of the experimental ratio of height.

13 is a graph of experimental thickness and resistivity measurements of TiN films with increased (111) crystalline texture, according to an embodiment.

14 is a graph of experimental hardness and modulus measurements of TiN thin films with increased (111) crystalline texture, according to embodiments.

15 is a graph of experimental hardness measurements of TiN thin films with increased (111) crystalline texture, according to embodiments.

16 shows experimental X-ray diffraction profiles of TiN thin films with increased (111) crystalline texture formed under different exposure pressures according to an embodiment.

17 shows the chlorine concentration depth profile of a TiN thin film with increased (111) crystalline texture according to an embodiment.

Claims (49)

A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: forming a TiN thin film on a semiconductor substrate by exposing the semiconductor substrate to one or more periodic vapor deposition cycles each comprising exposure to a Ti precursor at a Ti precursor flow rate body and exposed to N precursor at the N precursor flow rate, wherein the ratio of the N precursor flow rate to the Ti precursor flow rate (N/Ti flow ratio) exceeds 3, and Wherein the method forms the TiN thin film with crystal texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) crystal orientation corresponding to TiN The ratio of the peak height or intensity of the X-ray diffraction peaks exceeds 0.4. The method of claim 1, wherein the N/Ti flow ratio is 3-100. The method of claim 2, wherein the method is such that increasing the N/Ti flow ratio reduces the thickness of the TiN film. The method of claim 3, wherein increasing the N/Ti flow ratio reduces the resistivity of the TiN thin film. The method of claim 3, wherein the method is such that increasing the N/Ti flow ratio increases the Young's modulus of the TiN thin film. The method of claim 5, wherein increasing the Young's modulus comprises increasing to a value exceeding 150 GPa. The method of claim 3, wherein the method is such that increasing the N/Ti flow ratio increases the hardness of the TiN film. The method of claim 7, wherein increasing the hardness comprises increasing to a value exceeding 6 GPa. The method of claim 3, wherein increasing the N/Ti flow ratio reduces the chlorine content of the TiN thin film. The method of claim 3, wherein the method is to reduce the deposition pressure to increase the peak height or the intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) crystal orientation corresponding to TiN The peak height of the X-ray diffraction peak or the ratio of the intensity. The method according to claim 3, wherein the flow rate of the N precursor is 500 sccm to 10,000 sccm. The method of claim 3, wherein the Ti precursor flow rate is 100 sccm to 5000 sccm. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: forming a TiN thin film on a semiconductor substrate by exposing the semiconductor substrate to one or more periodic vapor deposition cycles each comprising exposure to a Ti precursor at a Ti precursor flow rate body and exposed to N precursor at the N precursor flow rate, wherein the N precursor flow rate exceeds 500 sccm, and Wherein the method forms the TiN thin film with crystal texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) crystal orientation corresponding to TiN The ratio of the peak height or intensity of the X-ray diffraction peaks exceeds 0.4. As in the method of claim 13, the ratio of the flow rate of the N precursor to the flow rate of the Ti precursor (N/Ti flow ratio) is 3 to 100. The method according to claim 14, wherein the method is such that increasing the N/Ti flow ratio reduces the thickness of the TiN film. The method of claim 15, wherein reducing the thickness reduces the resistivity of the TiN thin film. The method of claim 15, wherein reducing the thickness increases the Young's modulus of the TiN thin film. The method of claim 17, wherein increasing the Young's modulus comprises increasing to a value exceeding 150 GPa. The method of claim 15, wherein reducing the thickness increases the hardness of the TiN thin film. The method of claim 19, wherein increasing the hardness comprises increasing to a value exceeding 6 GPa. The method of claim 15, wherein reducing the thickness reduces the chlorine content of the TiN thin film. The method of claim 15, wherein the method is to reduce the deposition pressure to increase the peak height or the intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the (200) crystal orientation corresponding to TiN The peak height of the X-ray diffraction peak or the ratio of the intensity. The method according to claim 15, wherein the flow rate of the N precursor is 500 sccm to 10,000 sccm. The method of claim 15, wherein the Ti precursor flow rate is 100 sccm to 5000 sccm. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: forming a first TiN thin film on a semiconductor substrate by exposing the semiconductor substrate to one or more first periodic vapor deposition cycles each comprising a first TiN exposing to the first Ti precursor at the precursor flow rate and to the first N precursor at the first N precursor flow rate; and forming a second TiN film on the first TiN film by exposing the semiconductor substrate to one or more second periodic vapor deposition cycles each comprising Exposure to a second Ti precursor at a second Ti precursor flow rate and exposure to a second N precursor at a second N precursor flow rate, Wherein the method is to make one or both of the first and second TiN films have a preferential (111) crystal texture, so that the X-ray spectrum of the one or both of the first and second TiN films has a corresponding The ratio of the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN exceeds 0.4. The method of claim 25, wherein relative to the corresponding exposure to one or both of the first Ti precursor and the first N precursor during the one or more first periodic vapor deposition cycles, during the Exposure to one or both of the second Ti precursor and the second N precursor during one or more second periodic vapor deposition cycles is at a higher pressure. As in the method of claim 26, the first ratio of the first N precursor flow rate to the first Ti precursor flow rate (the first N/Ti flow ratio) and the second N precursor flow rate to the second One or both of the second ratio of the Ti precursor flow rate (second N/Ti flow ratio) is from 3 to 100. The method of claim 27, wherein the method is such that increasing one or both of the first N/Ti flow ratio and the second N/Ti flow ratio reduces one or both of the first and second TiN thin films The corresponding thickness. The method of claim 28, wherein reducing the corresponding thicknesses reduces the corresponding resistivity of one or both of the first and second TiN thin films. The method of claim 28, wherein reducing the corresponding thicknesses increases the corresponding Young's modulus of one or both of the first and second TiN thin films. The method of claim 30, wherein increasing the Young's modulus comprises increasing to a value exceeding 150 GPa. The method of claim 28, wherein reducing the corresponding thicknesses increases the corresponding hardness values of one or both of the first and second TiN thin films. The method of claim 32, wherein increasing the hardness values comprises increasing to a value in excess of 6 GPa. The method of claim 28, wherein reducing the corresponding thicknesses reduces the corresponding chlorine contents of the first and second TiN thin films. The method of claim 25, wherein for the first TiN thin film, the peak height or the intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN is in relation to the (200) crystal orientation corresponding to TiN The ratio of the peak height or the intensity of the X-ray diffraction peak is higher relative to the ratio for the second TiN thin film. The method of claim 25, wherein the exposure to one or both of the first Ti precursor and the first N precursor during the one or more first periodic vapor deposition cycles is less than about At a first reactor pressure of 5 Torr, and wherein the exposures to one or both of the second Ti precursor and the second N precursor during the one or more second periodic vapor deposition cycles This is at a reactor pressure of greater than about 5 Torr. A method of forming a thin film comprising titanium nitride (TiN) by a periodic vapor deposition process, the method comprising: forming a first TiN thin film on a semiconductor substrate at a first pressure by exposing the semiconductor substrate to one or more first periodic vapor deposition cycles each comprising exposing to a first Ti precursor at a first Ti precursor flow rate and exposing to a first N precursor at a first N precursor flow rate, Wherein the first TiN thin film has a crystalline texture, so that the X-ray spectrum of the TiN thin film has the peak height or intensity of the X-ray diffraction peak corresponding to the (111) crystal orientation of TiN and the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN. The ratio of peak height or intensity of ray diffraction peaks exceeds 0.4; and forming a second TiN film on the first TiN film at a second pressure higher than the first pressure by exposing the semiconductor substrate to one or more second periodic vapor deposition cycles, the one or more Each of the second periodic vapor deposition cycles includes exposure to a second Ti precursor at a second Ti precursor flow rate and exposure to a second N precursor at a second N precursor flow rate. The method of claim 37, wherein the second pressure is greater than 5 Torr. The method of claim 37, wherein the second TiN thin film has a preferential (111) crystal texture, so that the X-ray spectrum of the second TiN thin film has a peak height of an X-ray diffraction peak corresponding to the (111) crystal orientation of TiN or The ratio of the intensity to the peak height or intensity of the X-ray diffraction peak corresponding to the (200) crystal orientation of TiN is lower than the corresponding ratio of the first TiN thin film. The method of claim 37, wherein at least a first ratio of the first N precursor flow rate to the first Ti precursor flow rate (first N/Ti flow ratio) is 3-100. The method of claim 40, wherein a second ratio of the second N precursor flow rate to the second Ti precursor flow rate (second N/Ti flow ratio) is lower than the first N/Ti flow ratio. The method of claim 41, wherein the method is such that increasing one or both of the first N/Ti flow ratio and the second N/Ti flow ratio decreases one or both of the first and second TiN thin films The corresponding thickness. The method of claim 42, wherein reducing the corresponding thicknesses reduces the corresponding resistivity of one or both of the first and second TiN thin films. The method of claim 42, wherein reducing the corresponding thicknesses increases the corresponding Young's modulus of one or both of the first and second TiN thin films. The method of claim 44, wherein increasing the Young's modulus comprises increasing to a value exceeding 150 GPa. The method of claim 42, wherein reducing the corresponding thicknesses increases the corresponding hardness values of one or both of the first and second TiN thin films. The method of claim 46, wherein increasing the hardness values comprises increasing to a value exceeding 6 GPa. The method of claim 42, wherein reducing the corresponding thicknesses reduces the corresponding chlorine contents of the first and second TiN thin films. The method of claim 37, wherein the first pressure is less than 5 Torr.

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